We are seriously considering the purchase of a 5th wheel and pre-positioning it at a rural site for living off the grid. I know they aren't great from a security standpoint, but my visits to inspect used models have really captured my interest. Some of the modern conveniences available in these trailers is nothing short of impressive.
I looked t a 38 foot model that had a bedroom for two, two sets of bunk beds, a spacious living room, a good sized kitchen, full bathroom, and plenty of storage and a small stackable washer/dryer. This model had slide outs that greatly expanded usable space.
We got the idea from friends of ours who bought a 5th wheel, placed it on their property, built a deck around 3 sides. They added a roofed over screen room with a grilling area, an attached wash shed for a washer/dryer and bathroom, etc. They lived in theirs for several years before moving into a house and then sold it off for almost as much as they bought it for (and these folks were financially successful).
What's your take on doing something like this as an alternate living arrangement? We would look into adding solar and an efficient waste management system. Not sure of our total cost just yet.