So you ARE saying that if you have an upright canister stove, more propane will burn off early and less butane, so over the life of the canister, there is more butane left behind, effectively raising the vaporization temperature. So once only (or mostly) butane is left behind, the vaporization temperature is pretty close to that of butane, 31F.
Yes. If your secondary fuel is regular butane.
So don't use regular butane. See point #1 in my blog post (linked to in the original post).
And the result is that the canister just wouldn't work on snow trip.
Well, it's not quite that simple. It depends on altitude, the fuel you're using, the outside temperature, and what techniques you use to keep the canister warm. I have another blog post where I tried to tie all these disparate things together. See
Canisters, Cold, and Altitude: Gas in a Nutshell I'd take my Coleman Fuel pump type stove on any winter trip. Those will always work in the snow.
You're always pretty safe there.
HJ
