The limitations of cannister stoves in cold weather are well known. You might get away with a cannister stove if you baby it. For casual use, it might work for you; but for life-or-death, it's pretty dicey. Liquid fuel is the choice for reliability.

When I had a Svea, I'd pack a little square of 1/4 inch plywood to set it on. It kept things stable in snow, and provided enough insulation to keep the tank warm. Perhaps that might help with a cannister stove?

Here are some real-world reviews, including cold weather use, of the MSR Pocket Rocket from Mountain Equipment Co-op customers. Mostly, they echo the comments posted above. They suggest a range of cold-weather tricks, including keeping the cannister inside your jacket, laying on hands to warm it during operation, and putting the cannister in a small pan of warm water.

http://www.mec.ca/Products/product_detail.jsp?PRODUCT%3C%3Eprd_id=845524441932337&FOLDER%3C%3Efolder_id=2534374302696549