I'm 95% sure I'm going to go with a shipping container cabin now. Still futzing around with the design, though. And have to figure out what to use for a foundation; I suppose it should be off the ground, so maybe something under the corners and in the middle? I wonder if anyone out there does the spray on foam insulation, and how well that would work on the outside, with maybe a layer of stucco over the top. And of course I'd need someone to weld on a big raised roof for water catchment.
I'm currently planning to get back out there the week between Christmas and New Year's, perhaps longer depending on how my vacation time accumulates. I don't think I want to stay in a tent this time, though; it's going to be cold!