We're talking 0 degrees F, right? Yes F.
Not great for fuel I have 2 1/2 achers of land When I bought it There was only weeds no trees no knowthing. that was about 5 years ago. now we have 19 fruit and nut trees and around 12-15 cottonwoods
Hopefully I can have some fuel latter but it wont be much.
I am all for Redundancy it would be great if I could get 2 or more things in place. Rocket mass heater for sure heat sink yes! not sure about the geo thermal though It is expecive and alot more work to install.
I like your idea for a aquaponics as additional heat sink and would love all the benifits from it as you metioned (and the fish waste a valuable nutrient source for the plants. You'll have the space! Is this on your wishlist?) yes it is
It is all about time and money! lol we will see . Thnks for the help