My family has done this in two states.  

Most states in rural locations have a barn law.  Barns or outbuildings are not held to the same codes, almost none really.  About none does it get you around assessments and taxes.  Some farmers will build partial barns with canvas style roofs to get their barns classified temporary to avoid the tax thing.  

Here's the problem, no state allows you to resell a temporary structure or barn as a residence.  That goes for rentals like a hunting cabin as well.  If you live there, eventually they are going to get around to you and yep, its usually the country EPA guy over waste disposal and odds are due to all sorts of reasons some of them very nafarious like cousin Billy Bob does septic systems, they're not going to accept any solution you have, none.  Its quite bizarre too when you consider in the country we built, we couldn't use portipottis but the next land over the guy could dump his septic tank pump out business over his entire field.  Its like if people live there, its gotta be this one or the highway no matter what.  

Excuse the pun but it was so much shit, we opted to build to code, actually exceeded it on things like insulation, and do the permit thing and we got our investment out of it when we sold it.  It was damn crazy we had a 1,200 sq/ft cabin sitting on top of a 4 bdr house septic system but we did it.  The country was using that, you never know who'll or how many will live there thing.  

Anyway, that's the biggie, waste disposal.  You need to address that before you dig a hole or drive a nail if you plan on someone, anyone, or even anyone can in the future live there.  Otherwise you are better off putting a camper on there and leave the wheels on, which, btw, is not a bad idea period since you can stay there on those long weekends as you build.  Campers are considered movable so temporary.  Hell, the one I bought sit there 25 years.  Nobody ever lived there and I simply waited for a rain and hit the drain on the tank.  Why the hell not?  Next farm over he used the same fields to dump his septic trucks.  

Now a lot of counties don't allow campers/RVs.  If that's the case, sorry, you bought your land in the wrong county for doing an off the grid cabin.  They're going to be in your shorts on everything.  No camper laws pretty much are like HOAs and intended to keep property values up which means whatever you do has got to be pretty and fit in or they'll be in your shorts.  Used trailers for example, those type folks hate.  We knew a couple that made it three years with no running water or septic system in a used trailer.  They were a very secluded location but they found them and nailed them.  They had dug an outhouse and were using a running creek for water.  About everyone bans outhouses now.  Heck we tried the composting toilet approach which the county nixed because they said there was no method to dispose of the compost.  Amazing when you consider the septic pump out guys disposal method.  

Anyway what we did was buy one of those prefab two story outbuilding things, actually in OH it was Amish, bought vinyl insulated log siding which they put on there at initial build for no extra cost, then we finished the inside.  We used through wall heat/AC unit like a motel, wired it up to code, they didn't give a crap about the plumbing but we had nice things like water cut off and drains for winter, etc.  We used RV appliances to save space so had dual to tri power aspect.  Added an almost doll house picturesque front porch towards the road but a nice wrap around back deck for additional living space.  It had very nice block basement too. Used beaded board for the walls, super nice.    Not including the land, we had a whopping $40,000 in it, over half that was just the septic system and basement.  Man it turned out super nice.  The people who bought it moved family right in.  IT was amazing cost effective with not even lighting a match a maximum electric bill of about $60.  It was so insulated, it was like heating or cooling a boat.  No freeze low limits was like $8 a month.  

Here's the steps:

1. Find the land.  This included checking county regulations to build what and talking to the neighbors about, most important, water.  Its at this stage before you buy, you got to get a handle on septic system.  How much land, type, etc. just so you have an idea.  

2. Buy the land, get a temporary power pole put in.  This is so you can build.  Going all mountainman hand tool isn't going to work and I'll tell you why later on.  This also gives you the power you need to work the well.  Its at this point you can put a used camper on there.  

3.  Dig a well.  Its all for naught if you can't find water.  Until you are ready to build, it prolongs your stay time by not having to haul water in.  Man, I did that haul thing for years too but that was just weekends.  

4.  Here's the killer, now have the country septic person come out and pick your spot for the septic system.  That's a couple hundred dollars right there.  Now depending on where, that's typically when the whole damn clock starts ticking.  Learn the clock before you do this step.  They're going to give you so long to get the septic in or its do the whole what and where thing again and then there's a clock on how long you have to hook up once you get it put in.  

5.  Now you can build your cabin.  Leave the walls off till you get the wiring inspected, plumbing, it depends but not so picky on that.  Now most folks want to like consider their structure like a barn/out building till they're ready to do the septic and water.  The problem with that is you won't know where either are going to be.  Wrong guess there and your cabin becomes a barn till you build another one.  Heck, our build was in an open field and it was an issue.  A better approach is a halfway measure.  Our first project, we built a pole barn to initially act as a materials storage place, later it would become a garage, with a side living space we used for living then it became storage.  Then later we built the permanent structure, yep, close to the water and septic.  That worked out real nice as we got a taste of both worlds, temporary and permanent, for a while.  

Now you know why on the cabin, we went with a Amish prefab outbuilding.  We met the damn clock with the structure then could take our time finishing her out, adding all those neat things you were talking about.  We bought materials on sale, when we had money, things like that and didn't let the country bankrupt us with their damn clock.  

Tell you how universal this is, I have a niece in Oregon right now doing the exact same thing.  They're living in a camper while they build their house as they can afford it.  Same steps.  Same get the rough structure up then you can back off and take your time.  

Now know there's only two ways this goes.  Either you are going to work on it now forever or let it all go to hell.  We worked on our family project for 25 years.  When we sold it, move my mom to TN, it had a main house, cabin, garage with MIL apartment, two story barn (another Amish project building), metal outbuilding one of those order it things like a car port except all four sides, shed lean tos off the two outbuildings,  two wells, two septic systems, and two electical hookups.  Hell we had two riding lawn mower, a small Kubota tractor, who knows how many tillers and farm crap,  generators, and on our place we had free natural gas.

My how we loved that place.  It was truly a labor of love.  It would be years before the first of us moved in and decades before the last of us moved out.  It is off a dirt road off a dirt road so far out in the country on a new moon night, you can't see your hand in front of your face.  It was so quiet, your ears would hurt and you could hear the not very noisey in the first place oil pump two miles away when it kicked on.  The game was so plentiful, I had to put 2" bars on my Jeep from hitting them and the largest deer taken was off the back porch of the cabin.  Sold to family friends, his head is still mounted in the cabin.  

The problem is that rural, work becomes an issue for the young and how far that damn closest hospital is for the old.  Still we don't regret it.  It was a hell of a ride.

Tj