I'm not far above sea level and Arkansas winters are pretty mild. The highest elevation in Arkansas, which happens to be a few miles from me, is just under 3,000 feet. I've got electricity, so I'll be warm enough unless the electric goes out. And if that happens, I have a relative about 40 miles away where I can crash if needed. All good suggestions on things I need to think about, thanks.

Even if I never live in it, I will make that mobile home useful since it already has electric and water. I won't be heating and cooling it, that's for sure. The living room can be a workshop and tool storage, etc. The kitchen sink can still be used along with a washing machine / laundry station in there. The big bedroom in back might make a good baby poultry brooding area until they are big enough to go outside.

My younger self would've loved the tree house, that would've been fun. Still plenty of other fun to be had, I'll make sure of that :)