You will need some batteries, but you can look into convection solar for heat. Batteries will be used for other things, but possibly for spot heat.

I think you should consider building a small, but well insulated building. Maybe like an 8' x 12'. Not big at all, but insulate it really well. No concrete tho unless it's an anchor below ground. Insulate the floor, side walls and the roof.

I have a small shed out by my garden. It's insulated pretty well. Cool in the summer and retains heat well in the winter. If I need a place to stay, I could move into that.