I do not live off the grid, but I do a lot of camping and have lived out of a car or backpack for months at a time for pleasure rather than necessity. I have friends who have lived in their cars in urban areas when they were homeless.

I am not sure that camping is less expensive than owning a small home in a lower-cost of living area. Free campsites are often difficult to get to, have no facilities, limit stays, and may be full when you get there. National Park campsites are expensive and crowded with inadequate bathroom facilities (imo). Private campgrounds that rent space by the month can get pretty pricey. While we were on our trip, we saw quite a few homeless families living at the KOA and it really surprised us given how expensive it was even at the monthly rate. If you qualify for a senior discount it's probably a lot less.

I think it's a great thing to do from a lifestyle point of view, but maybe about break-even from a COL standpoint. Maybe you could try it out for a week or two before you decide to sell your home?