Coldest I experienced was minus 40C (I think C and F meet near there) - We were SKIING in Quebec at Christmas. We were NUTS (no alcohol involved I swear).
They shut the slopes down when the wind at the top kicked up to about 20 - they said they were afraid the metal cable in the lift would break but I think they just didn't want the outdoor staff to sue them!
We went all the way up there to ski, so by god we were going to ski!
Interestingly the -90 we arrived on, and the airport ops in general seemed to not notice the ridiculous cold.
I am seriously spoiled now, living in a southern state. I was raised, and learned to fly in the north. Sounds like one of those silly 'when I was a kid stories' but it is no bull that I used to get up at 4:30, drive to the airport in my subcompact, start the engine preheater, then commence to shovel snow around the 172 in the dark, deice the wings and heat the cabin. After about an hour, I would pour the engine oil back in, replace the nice warm battery I stored by the furnace all night, and try a start. Usually the plugs frosted over and I would have to pull them and heat them up, finally get a start (this time with the car battery boosting), then replaced the cowl and move all the winter starting detritis out of the way and blast through the drifts to the paved ramp, finish preflighting and deicing, and by then the instructor was ready to go, with hot coffee (for him only) in hand by about 8am!
I was "Dedicated".