TomD turned me on to WinterTrekking, a group out of Canada mostly. Since it is much colder up there, they can use less waterproof clothing.

I used my isobutane powered MSR Pocket Rocket on a five day trip in the southern Sierra in early Oct. The coldest morning was four degrees and after warming the canister a minute or less between my legs, I fired it up and when my water warmed up a little, I dipped the canister in the warmed up water and the stove instantly put out more heat/noise. I repeated this a couple times and got my water boiling for hot cereal in short order. With no wind finally that morning, that was the warmest morning while packing up camp.