Can an alcohol stove be used in the winter?
Yes. Left to right a Military SVEA burner and a commercial Trangia burner encased
in ice, running (try that with your Whisperlite). An alcohol stove is much more trouble free. So when you don't need a zillion
BTU's to melt snow, the alcohol stove will work fine.
Run times and Simmering: The Trangia burner will run wide open for about 25 minutes (a little less in
the summer, a little more in the winter). Add the simmer ring, but leave it fully open and the burner will run 1.5 hours.
It will run longer with the ring at 50%, but I've never bothered to time it. The key here is that you can cook lentils (bring
to boil, then close down the simmer ring to 50%) and other foods that might require a long unattended simmer time.