My two boys are probably it in terms of kids... there's a very very very slim chance for a 3rd, but I only seem to want one more when I'm ovulating, lol! I do wear DS2 for shorter outings, but there is no way either he or I could tolerate all-day wear, esp in heat.
I was thinking of a sit&stand, but can an exhausted child nap in that? Most of the time we'd use the stroller DS1 would probably just need some breaks, but there are 2 huge trips coming up that involve pretty much all-day walking. First is Disney World with our Florida family, and that's days of epic walking. I know that both boys will pass out at some point, and while I'm hoping we'll be able to take mid-day breaks this time, last time we were there from dawn until fireworks and I want a plan in case we cannot ditch the fam for naps.
Would traveling with a tandem be worse than with 2 strollers? Most outings involve another adult, so we could just use 2 strollers... but it seems like carting around 1 item would be simpler than 2.