Heating /= electricity. Most houses are heated via propane or oil, you could take a small propane or oil heater and bring the largest portable propane tank you can muster, or bring your own oil supply. Finally, living surrounded by forest would provide a great supply of firewood for a wood stove.

I work in siding, we use expanded polystyrene foam as insulation. 1" provides an R-value of 5.0 (fiberglass, which is in the majority of homes is only between 3.1 to 4.3) add a silvered side over an air gap (IE place it over a stud wall) adds R1 and if you take your time you can get an air gap in front and behind of the insulation making it an R6. Which is a considerable R-value boost with very little material.

You could literally flat-pack build your house. Plywood, baton, insulation, baton, plywood. This would get you about an R-11 wall within 4-5". The 4 walls, ceiling and floor made this way would get you a 6" cube that you could easily fit it in a truck bed. You wouldn't have to abandon your shack should loggers come by.

Given that I've worked on houses that were literally drywall onto stud with drywall + aluminum siding exterior. You'd do better in winter in my shack than that house lol.

That is pretty awesome, I took a building science course while studying structural engineering and I learned a ton about R values. There are these crazy building blocks with just astronomical levels to the point where it is silly. They don't even consider the numbers comparable because the ratio of heat that you lose when you open and close the door more than makes up the marginal difference.

As for the original point (free land!) I plan to build a very small cabin up north, but I really would prefer easy road access and electricity so I've ruled out the federal land route, at least for now.