What if fuel for heat for your home becomes too hard to get or expensive? Gary the retired engineer has a huge wealth of good information for very low cost projects and links to many others.
http://www.builditsolar.com/Experimental/PEXColDHW/Overview.htm
That is a nice system, solar is a good way to go for a lot of our needs.
And if one can’t afford the fancy solar systems, there is always a fire in the front yard and a bucket with water to heat it.
Or as I have to do, as I can’t use my wood stove and be on my oxygen machine at the same time, and I pass out, so don’t play much with fire, you will wear 3 layers of clothing, wear a layer of plastic and keep your head covered.
If it gets too cold to sit up, the bed is there with its sleeping bag and a plastic bedspread [a good Walmart paint drop cloth] to seal the body heat in.
One survives, if one wants to do so.
My old wiring will not support electric space heaters.