For cold temps, and at altitude, you need a fuel with a low boiling point and high vapor pressures. Of the bottled gases, propane is the best in those regards, and by a fair bit. Butane is the worst. Isobutane is in between. Many of the canister gases (not propane canisters, but the smaller ones) are mixtures of those three, but what happens when you use them at cold temps or at altitude is that you ultimately end up carrying dead weight because the propane that's in them will burn up first, and then your partially-used canister becomes useless because the remaining gases won't burn.
White gas, on the other hand, is an excellent winter/high altitude fuel. That's why I switch to a white gas stove in those situations.
It's also why I don't carry "fancy" lighters. They all run on butane, which is horrible in cold/high alts. When I'm in the backcountry, you'll find Bic lighters in all my packs and on my person, along with stick matches in a waterproof canister. The Bics also run on butane, but they are cheap enough that you can stash them in multiple places. The stick matches are for cold and high altitude because that's the only reliable ignition source I've found (other than flint and a striker).
Stay safe out there, gents!
