Oatnet had a better idea. Convert a VW van to electric. Those vans make a great minimal RV. I actually removed the sink and all that junk from mine. I just made a big bed out of the back, and set up the chuck wagon outside on a folding table. Used to camp all the time with 3 big dogs. Everything we needed fit under the front half of the bed platform. If it was pissing rain out there, then we could cook inside. Generally it was just make a sandwich in such times though. It's camping, not living in it long term.
To make a trailer into an RV, it would have to have front wheel drive. Then it would ride like shit, because trailers do not have shocks.
But any small trailer could be made into a decent lightweight camper, that would be towable behind smaller cars that have a manual transmission. Or medium size cars with auto. Make it 4" tall max, and possibly a pop up to full height for use.
Boat trailers and such make great candidates for that kind of thing. They are light and long.