I have been thinking about this for years and think I have a great trailer in mind, start off with a Wells Cargo trailer, at least 10'x12', insulate it, put 2 fold down bunks on the each wall, so they can be folded up out of the way, when in transit, put some mounts in the floor for a table or chairs, in the front of the trailer I would build a at least 4 shelf, about 4" deep for sundries, and and fold up table about 4' by 4', to fold up against the shelves to prevent anything from falling off, and a good cook table when let down on jack chain. I would get the trailer with the fold down rear door ramp, and one side door, with the bunks folded, I think a 4 wheeler would fit just fine. Now to the nice stuff, mount some shades on the roof that will cover one side and the rear of the trailer, once on site, unfold them and set up a nice shaded dry place to hang when the weather cooperates, and at least keep things dry if it rains. You need a vent on the roof, and can mount your propane bottles on the tang on the front of the trailer, even a generator. A Coleman stove would be just fine, as long as you open the vent. Gun storage would be nice and not too big a problem.
My dream.