The best building material is rock just because of the chemical bond being so strong in rock. And it's water proof and insulates well.
Caves are the easiest rock houses to build. They require no heating or cooling. Especially if you have a cave 500 meters below the surface of the earth which is 65 degrees year round or warmer. The only problem with that is air flow which is needed for toxic gasses. That's why you need a canary when exploring mines.
Light: Use LED and solar energy.
Shower: Just have rag and water. And wash every day to get rid of oil and sweat and dead skin cells.
Toilet: Just dig a hole 100 ft. from a water source.
Food: Gather nuts and berries and hunt and fish. And dry the food for storage. Boil to rehydrate.
Cell phone: Don't bother, you're on your own.
Just find an abandoned mine in Alaska or make your own with explosives. Caves close to the surface are usually 50-55 degrees year round.
