Still having trouble with my math...is it 2 adults, and 5 kids or 2 adults and 3 kids?
We used to camp out of the family Chevy, then Ford van, with two tents, an outdoor kitchen and gear. Man the packing and unpacking gave me unbelievable small space management skills! A place for everything and everything in it's place. An Excel spreadsheet checklist for all items for each camper to be sure we didn't forget anything. I wouldn't trade that hassle for anything...
Except a large enough trailer to haul everything and provide secure overnight shelter!
A fellow suggested years ago, that we consider a small cargo trailer for the camp gear, keep it loaded except for foodstuffs, hook up and go. Well that idea, led to the cargo conversion, since their wasn't anything in the market that would sleep 6, haul gear, fit our tow weight limit, and most of all the budget.
Ditto the Livin' Lite recommendation above- Camplite: here's an example: their 21 BHS sleeps 6, and is all aluminum construction and has the mor-ride suspension, and I think there is an "off road" upgrade available.
http://www.shadymaplerv.com/product-livin-lite/camplite-travel-trailer/cl-21bhs
Here's a non-bunkhouse on closeout closer to home:
http://www.southlandrv.com/2017-thor-industries-livin-lite-camplite-21-rbs-ultra-light-travel-trailers-for-sale-atlanta-georgia-637.html
A used bunkhouse slide Camplite in NC:
https://www.rvtrader.com/dealers/D-%26-H-RV-Center-2972996/listing/2014-Livinlite-CampLite-Camplite-Travel-Trailers-21BHS-121947779
When our kids were little we could stack them up most anywhere, well they grow fast, and bring friends, and more and bigger stuff...then they hit late teens and it's a struggle to get a trip organized.
I like the idea of the camper as a base camp, with your tow rig available for more aggressive adventures, leaving the trailer to be your refuge at night. Agree on A/C for the hot nights. A friend suggested only to run the A/C in the evenings for comfortable sleeping, otherwise you'd be constantly running the kids back outside during the day.
Good Luck on the project.