Been there. Our kitty was 10 yo when she started her life as a camping kitty.
In our case the tow vehicle was a Ford Excursion (= BIG). We would put the smallish travel litter box in the cargo area with some water and food. Once we started the trip she would be released from the travel carrier and wander the Ex.
At the campground she would have run of the TT which was a 25'.
Now we have a Class A and our new kitty (our old girl died earlier this year) is right at home running the length of the motor home.
Moral: kitties are very adept at camping.