I live in Ontario where we go down to -30C in the harshest conditions.

We have a heat pump and a furnace and they alternate based on efficiency

Somewhere around -5 to +5 C it switches from the heat pump to the furnace

I think you could get by a bit colder but it really loses out on efficiency vs burning gas unless you invest in a geothermal heat pump

Wtf? This is a weird take lol

You could definitely do clever things to obfuscate what you’re doing, but it’s much easier to replicate building the image as there are no external dependencies, if you have docker installed then you can build any docker image

When you make a docker image and push it to dockerhub all of the instructions it took appear there so it’s very transparent, also super easy for any person to build it themselves unlike executables, just download the Dockerfile and run a single command

Besides the obvious of telling your users to build the exe, have you considered alternative distribution methods like docker?