How about a wall tent? I went from a 2019 Forest River xlr toy hauler to a canvas wall tent on a platform and liked it more. I mean, no a/c, but i had solar lights, an charger for phone, you could probably do a pv system or propane for a fridge, coleman stove. Little wood stove, was alright. Site selection is more important for sure.
You could sell it to the kids as going "camping". Everyday were camping, yay! I bet with everything its still cheaper than an rv by alot, and can be packed up and put in a truck bed.
My project back home is a 93 bluebird schoolbus to setting for long term off grid camping. Thats built a lot better than the toy hauler.