I think the answer to this question was realized last night when I was forced to make a decision on whether or not to cancel my chamber choir rehearsal.
The air temperature settled in at around -30 c last night (-22 f), and with the wind chill it felt like -46 c (-50 f). Today the air temperature was below -40 (both c and f) again, but at least the wind has slowed down. However, the ice fog made the visibility near nil. Most things in the northern metropolis continue as usual in any winter weather - we are well seasoned here, and bundling up in this weather to take on the elements gives us all a sense of pride, and helps us laugh at the places south of us that shut down when a half-inch drift of snow passes over them. "Wimps" we say to them.
However, far be it from me to make a chorister drive in these conditions and risk being stuck "out in the cold" after rehearsal. Let's not be fooled here, this weather can KILL people if exposed to it for a length of time. Tow trucks and service vehicles are so backed up, that if you did get stuck, you might find yourself stuck in your car, wherever you are for up to four hours.
So, the decision was made, that for the first time in my history with the choir, we canceled as a result of the weather. With only three weeks left until the concert, this is a little unsettling for me, but I still think we'll be in fine shape. There is one empty weekend left between the next two rehearsals, so if I feel we must - we can rehearse on the Saturday morning.
Sending you all warm thoughts on this most miserable of miserable cold days.