Eh well, that depends (of course).
Boiling pts:
Butane : -0.5 C
Propane: -42 C
Obvious operational difference here!
Ahhh, my choice would be the Propane. IF I were to attempt those frigid temps ;-) My friend in the north country does it every year.
I would never share the warmth of my feet with a canister :-) I would use an alcohol stove that does not require warmed fuel. I know alcohol stoves so I can do it ;) (companion burner with copper wick incorporated onto surface of stainless steel mesh) or Fancee Feest stove with piece of copper wick in center of stove. In the future, I may try a frozen butt hang up north with a propane stove just for the fun of it.
BUT for actual use with an inverted canister stove, it depends on how warm you kept the canister before use.
That’s the fiddle factor most frigid(-20F) weather trekkers put up with. It’s what they have to do. IF you had a small 300 gram canister of propane, no more fiddle factor. The canisters have a lindal valve. No need to sleep with them or carry them next to your back.



helps prevent flame liftoff

