Canister stoves can work in those colder temperatures - we just used one in Yellowstone and temperatures were as low as -14° one night.

There are tricks, though:

- You need a stove with a remote canister (e.g. the Primus Multifuel) and you need to turn the canister upside down (so, the valve and line are at the bottom)
- The stove needs a preheat tube running through the burner

This lets the stove pull the liquid components of the canister fuel out and make use of them efficiently, whereas if the canister is right-side-up, you only get whatever is still gas, and the liquid stays at the bottom of the canister.

It helps (but isn't necessary) to put the canister in some lukewarm water if you have it, or to put a chemical hand warmer on top of it. And, either way, you'll be better off with a heat sink pot (like the Primus ETAPoweror Jetboil GCS pots), or the MSR heat exchanger, plus good shielding from the wind, which will help increase efficiency.

With all that in place, the canister stove will work quite well for melting snow for water - about as efficient and fast as the liquid fuel stoves. We generated water for a group of six with a single stove set up this way several nights in a row.

This setup is also just as safe as Jim's for cooking in a vestibule (we used the canister stoves inside igloos as well).

Oh - and canister stoves work *better* at altitude - that (and the fact that they're less fiddly) is why they're the stove of choice on Everest and other high mountaineering destinations.

As for the liquid fuel stoves, they certainly can crank out BTUs for melting snow, and they're probably better at really extreme temperatures, but more and more I'm starting to see the value in sticking with canister stoves. The last blizzard I was in, I was grateful for the canister stove (a Jetboil) that I could use - carefully - inside my tent.