Kids are finally old enough (4 and 7 years old) for some short backpacking trips, and I'm in the market for a replacement tent or two. We went on our first backpacking trip this week using old gear my wife and I bought before our kids were born: a 6.5lbs 3P for my wife and kids, and a 3.3lbs 1P for me. The rain fly on the 3P came apart after 10 years in storage, and the 1P was basically a glorified bivy sack with no room to sit up and no room or vestibule for gear storage. Both had been purchased cheap at REI garage sales a decade ago, so I'm ready to write them off and upgrade to some better gear.

I'm curious which way to go with tent setups that will last at least 5 years: a single 4P vs two 2P vs a 3P and a 1P. Currently looking at variants of the MSR Hubba/Mutha/Papa Hubba 2/3/4P series and Nemo Dagger 2/3P. Marmot also has a Tungsten 4P. However, I first need to figure out the best sleeping arrangement before I can decide on a specific tent, so I'm hoping anyone with experience backpacking with kids can offer some advice.

Ounces aren't a primary concern since distance will be limited by my youngest, but pack size is since the 7x23" 3P took up half of my pack.

I've used the Alps Mountaneering tents with great success but we've only done car camping so far. It might be easier to get two 2-person tents if weight is a concern.  If either of your kids are in Scouts you can get a discount if you sign up at hikerdirect dot com.  I had a 30 year old Eureka Timberline that bit the dust and didn't want to spend a fortune on the REI stuff.

Forgot to mention that we already have a 6 person car camping tent, so this would be strictly for backpacking.

This is actually kind of a challenging situation you are in, since the kids aren't big enough and there packs don't have a lot of room to carry real gear.  You and your wife will be porting the gear, plus the camp stove, etc.  Rather than getting two tents (twice as much rain fly, more weight in poles, more weight in ground sheets) I'd suggest getting the biggest but lightest 4p tent that you can buy.  Aluminum poles for obvious reasons, Eureka has some long proven backpacking tents that are robust, not too heavy, and durable enough for more than a few seasons.  If you don't already have the best / lightest bags you can get, that's another focus area, along with lightweight sleeping pads.  I've never back packed with kids, but did a lot of longer backpacking trips when I was younger.  Even splitting the gear for two adults doesn't leave a lot of room in packs for anything else unless you are only going on a single overnight trip.

Yeah, the two adults carrying the gear takes up pack space quickly. My youngest was able to carry his sleeping bag for a total pack weight of 3.5 pounds, and my oldest was able to carry his sleeping bag, sleeping pad, a little water, and some clothes for a total pack weight of 12.5 pounds. My wife carried the 1P tent, while I carried the 3P tent. There's no way I could fit a tent much bigger than the 3P, but two smaller tents split between the two of us should work. Also, a 4P about the same size as the current 3P would free up space in my wife's pack that the 1P was occupying.

I would say either 2 2P tents, or a 2/3P tent plus a tarp.

I hike with trekking poles and will sometimes use a MLD TrailStar, yes, I know it's expensive for something without walls, but it weighs just over a pound with stakes, can accommodate 2 adults prone in the rain, and 2 adults plus 2 children for cooking in the rain.  Add 3oz for a mosquito net that clips to the center support pole and covers your sleeping bag.

Let the kids or kids+wife have the tent.  The 2 kids can easily double up on one 25"x72" spot inside the tent.

7 years old is not too young to be carrying water plus clothing on extended backcountry hikes.  I would try to leave the youngest as unencumbered as possible.  

I did this a few years ago for my family of 4.  Went with the Tarptent Hogback.
https://www.tarptent.com/product/hogback/



Huge 4 man tent 86x86
Weighs just over 4lbs.
It is so simple to put up, and really well thought out.  It's so simple I even like to use it car camping in campgrounds, even though I have tents more geared to that.  It really is nice.

How about a 4P pyramid tarp tent? No extra weight of poles needed since you use your trekking poles, they tend to be very large with great headroom, and if made of DCF very light and strong. Drawbacks? DCF is translucent so privacy can be a concern, and they don’t have floors or bug screening. (They can be bought but that’s more cost and weight.)

Thanks everyone for the suggestions.

The Tarptent Hogback looks nice, but they are out of stock with no word when they'll be back.

The MLD Supermid with Innernet looks interesting, but they are quoting 10-14 weeks.

The MSR Papa Hubba and Big Agnus Copper Spur 4 are sold out almost everywhere with a handful of sites possibly having some new old stock. Makes me wonder what's going on with 4 person tent availability.

Big Agnes Copper Spur UL4

Speaking of the Copper Spur, I have the 1 and 2, but old models, probably their initial designs.  Nice design.  Good quality.  My 1 and 2 are pretty small, to keep the weight down.  I checked the new CS 4 and it's actually got a really nice size at 96x86.  Impressive.
I like the Hogback's single wall design where you put the tent up in once piece.  The Copper Spur you put up the tent body first, and then the fly on top.  If it is raining, that can be a pain.  The hogback goes up so much quicker and easier than the CS.
My Copper Spurs have pretty low vestibule heights so you really have to get down on your knees to get under the fly opening and into the door.  It looks like the new 4 has fixed that as well.
My CS has pockets in the fly that you put the cross pole into.  You really gotta stretch that fly to get the pole in there.  Almost feels like you're going to eventually tear the fly putting it on.
The only downside I have with the Hogback, is they only offer a pre-cut Tyvek footprint.  I do like the Nylon footprints with pole grommets better.  The Tarptent Tyvek is a bit of a pain to fold up and take with you.

https://www.campsaver.com/msr-papa-hubba-nx-tent-4-person-3-season.html
1 left!

You were right, there really isn't much in stock anywhere.  I'm still looking.

Nemo make some excellent UL tents - not sure if they stretch to a 4.  

Marmont ultralight tungsten 4 is OK too.  

With most of these UL tents it pays to get the "footprint" particularly with kids as the standalone base can be fairly thin.

https://www.backcountry.com/big-agnes-copper-spur-ul4-tent-4-person-3-season?skid=BAGZ29C-ORA-ONESIZ&ti=UExQIENhdDpUZW50cyAmIFNoZWx0ZXJzOjE6Mzc6YmMtdGVudHMtc2hlbHRlcnM=
3 left

https://www.backcountry.com/klymit-maxfield-4-tent-4-person-3-season?skid=KLTE00C-ORAGRE-ONESIZ&ti=UExQIENhdDpUZW50cyAmIFNoZWx0ZXJzOjI6MTE6YmMtdGVudHMtc2hlbHRlcnM=
I've seen this guy in a few different places, but I don't know anything about it.

A lot of places are pushing out coupons now too.  I got a Campsaver 20% this week, REI starts 20% today.  I'm sure the others will be sending out coupons to keep up with REI too.

mountainsmith genesis 4

Thanks for the help everyone. I ended up getting the last MSR Pappa Hubba 4P from Campsaver with a 20% coupon. MSR even still has the footprint for 40% off. They even have the Fast and Light tent body replacement for 60% off. Anyone think that's work picking up while I have the chance?

https://www.msrgear.com/msr-warehouse-sale/hubba-fast-and-light-body/hubba-fast-and-light-body.html

I think that's a personal choice for you and your family.  Mine wouldn't want to use it that way.
ETA:  And nice score on the tent!

You could roll with tarps, unless really bad weather coming...

I agree. Tarps are good training for the kids. We camped in them half the time in Scouts.

If you have the bucks, the basic shelter is 1.4 pounds, and inner netting and floor are available for more money:

Ultamid

If you are on a budget, this is a decent tent, but 7 pounds:

Half Dome