I don't know that I would call my set up a BOB, more like a work mobilization kit. It stays packed/ready at all times, with typical BOB stuff (but not every usual BOB item) and some work-specific stuff.
When I go on vacation, it goes with me. I strip out some of the work-related items and add destination/travel-specific items. All of that, as well as a couple of changes of clothes, goes in a 5.11 Rush 72.
If I fly, which is rare, I lighten the load and switch into a smaller ruck (don't remember the brand...had it for years). Basically, it's small enough to carry-on. Items that won't make it through security get moved to checked, then reloaded when I get to my destination.
Last year the wife unit and I went to Hawaii. Having only been married a few months, she wasn't really adjusted to my "be prepared" mentality. I told her I was taking my ruck for "just in case." She gave me crap about it.
On the flight back, she said, "you really did take that pack everywhere...and it came in handy!" The ONE time I didn't have it with me (and OP, you being a medic like me you'll appreciate this) I sliced the crap outta my foot on some volcanic rock. No BOB. No IFAK. No BOK. No bandages, tape, anyting except a bandana (back in the car). And I was bleeding like a stuck pig. It was almost SHTF time for me because the wife unit was in the water and didn't know I had gotten out (so no help). I had to cross 200 yards of volcanic slag on ONE foot in a flip-flop, leaving a blood trail (I was surprised a shark didn't follow me onto land I was bleeding so much). I will NEVER make that mistake again!
Bottom line: you gotta tweak what (and when) you carry, everything from your EDC kit to your BOB to your third-line gear. You can't just throw it all together the first time and expect it to work. Hell, every time I come back from a trip I think of something different to do/pack/carry.
Envision your needs: food, clothing, shelter, water, weapons (defensive, offensive). Figure out worst-case scenario to minor inconveniences. Plan and pack accordingly. A trip to Hawaii would require different gear than a trip to Alaska. Some things are certainly the same, but many things are different.
Oh yeah...take a small notepad with you when you travel. Use it to take notes of EVERYTHING you learn about your kit, from what you need and don't have, to what worked, to what didn't.
There's another good thread in the SF..."My cross-country GHB." I suggest reading all of it...VERY informative.