Thanks Jim :-)
However, I do not agree with point 2:
> For temps between -40C (-40F) and -10C (+14F) use 100% propane and
> accept a substantial weight penalty.
My reason is that I have cooked below -10 C many times quite happily.
During the day I keep the canister in my pack next to my water bottles, which are close to my back. That means the canister never gets *too* cold, as the water bottles don't freeze. A good use for body heat which should not be ignored.
I always use a liquid-feed stove in winter, and they can run with a canister temperature down to about -24 C. Not strongly, but they can get going. As I usually manage to keep the canister warmer than the environment, this lower limit is not very limiting in practice/
I leave the canister exposed to the flame radiation and maybe sitting in a bowl of cool water - which is above 0 C of course. This means that the canister never gets too cold while in use. If you do this you MUST monitor the canister temperature for safety of course, but that is rarely a problem.
However, if you have a static situation where the canister is at -30 C (eg left behind in an igloo for several days during a cold spell), then you might have a problem. Will Rietveld uses a propane stove for this very successfully.