This is cool. I've been wandering around YouTube this morning looking at small, unusual houses. There is this guy Derek “Deek” Diedricksen who makes really tiny houses, with a 4x8 foot footprint, out of discarded materials and whole sheets of plywood. He has devised a fry oil heater for such a tiny house, which I saw in Episode 2 of "Tiny Yellow House" and then Googled because it was so cool. Fortunately someone else has covered it, so here it is:
Notice that he has fresh air fed from outside through a copper pipe into the stove, so it doesn't use up the air in the tiny house for combustion. He used a busted old cymbal for a reflector.
Here's his diagram!
So now you have a way to heat a tiny house, with fry oil. You might be able to get the used oil from restaurants for free (you'll have to filter it, but so what). You could also heat a separate bed-pod inside your home, i.e. a wood 4-poster or a house within a house and save on heat in general. You'd still want the fresh air feed and exhaust, but perhaps you could make an insert that fits exactly in an open window, air-tightly. Note, however, if you burn your house down this way it probably won't be covered by your fire insurance, so be extra careful!
I can see someone squirreling away a number of these over the course of several road trips, and that way they'd have a series of waystop squats if they wanted to travel lighter later. Or they could just have a big variety of places to sleep around town so they are unpredictable. If trying to be extra stealthy you'd have to figure out how not to have your car parked near the house - maybe take a bike with you or hike to it. But with the heater, this could be an all-season activity, and it's a step up from camping.
Note from JWR:
7 minutes ago