Our early retired life was spent moving a lot, we traveled in 45 states in 4 years, including Alaska. In that case, a motor home was imminently practical, as it's much easier to park and set up than a trailer (built in leveling jacks, back-up cameras, etc). Nowadays, our traveling is somewhat constrained by the cost of fuel, we don't travel as often, and your idea makes good sense. Many folks do just what you suggest.

Terrain is flat. Line of sight is blocked by tree trunks to all APs and to each other.

Thanks for the on-target comments. My anecdotal experience here agrees with your research. Given the canopy of trees here, I don't think a 70 foot tower will improve things, but the concept sounds perfect. I have done some strength charting using stumbler, but only outdoors. Last year, I personally used an external USB WIFI dongle to get above other RVs and outside my own walls, and given that we were about 5 rows away form the nearest AP, it worked OK. There are still areas in this park without any signal. I'm thinking that a mesh system will allow us to fill those in.

Our choice is motor home, and we tow our car behind it. Trailers small enough to tow behind a car (say, a Prius) are not big enough to enjoy life in, IMO. You'll need a heavy duty pickup or larger for snow bird type trailers.