Unless you keep the canister close to your body under your jackets, even the current fuel mix sucks. People undertake any number of workarounds for this but I'm still the curmudgeon who likes his white gas stove. The cold weather process for that prettey much just involves letting the burner piss on the whole stove and setting it alight to warm the generator enough to keep humming. Spare fuel can be stored cold.
If you're made of money, MSR's current multifuel stoves than can run isobutane or various liquid fuels are neat, reliable, and give the most options possible.
If isobutane is used, remember to also sleep with it in your bag. Trying to hand-warm a canister at the crack of dawn is no fun.