THAT CAN'T BE RIGHT - AKA NO IT'S NOT GOING TO BE THAT COLD
For some reason I don't think that's right. Being that -73c is like -99f - we would all be dead. The worst it's ever been here is -47.8c or -54f (wind chill -58f). Dropping to -73c in one night would cause structural failure of buildings. My brother (god rest his soul) has experienced -64c weather and that's -83f. It literally cracked his leather jacket.