What Davydd said so well X2. We down sized from 5th wheel and truck three years ago just to be able to go for a "few" weeks. We now are in the B for 6 - 7 months a year. We dump and fill up every 4 to 8 days and in Quartszite this winter it was 10 days. I begrudge paying for camp sites when not required but will pay to have the right location, like Sedona etc. You learn to pack what you need and nothing else (except golf clubs).
40 years ago an 18' trailer was large...our unit is 20' long so about the same. Some can handle small spaces and some can't. We travel about 15,000 miles a year and are having a way too much fun to stop.
Good luck!