Functioning in sub zero temps, whether *C or *F, is challenging !
After 11 years of acclimatization, from a sub tropical environment to current "home" conditions, I can definitively say that I am now comfortable at -20* if dressed correctly, but add significant wind & things become uncomfortable quite quickly.
January/February generally bring us at least 2-3 weeks of -35* or below temps.
The only fun side of this is riding to work on "square" tires !
Paul.
"Kids who grow up hunting, fishing & trapping, do not mug little old Ladies"