When we lived in Montana, everybody knew that when it got cold, the little electrons in the wires got cold and sluggish, slowed down, some even hibernated, and the wires contracted in the cold reducing their capacity to carry electricity. To make matters worse, the atoms in the wires started eating up the electrons in order to have enough energy to keep themselves warm, leaving fewer electrons to travel down the wires to our house.
More seriously, in '85 I spent the night in a motel in Iowa in December. Woke up about 6:00, couldn't sleep, so decided to get back on the road. Went out to start up the little VW Rabbit pickup and the key barely turned in the door lock. Got in, again the key turned with resistance in the ignition switch, but the battery was good, cranked the engine, it fired up. Had to turn the key back to the run position, the spring in the switch didn't have enough strength to overcome the cold lubricant in the switch. When I let the clutch out, the pedal came up slowly and when it engaged, the engine died from the load of the thick oil in the trans. Had to sit there with one foot on the clutch and the other on the throttle for maybe 5 minutes to warm it up before it would idle with the clutch engaged and the trans in neutral. Started down the road, hit the turn signal which moved with some resistance and after my turn it didn't cancel--I had to pull it down.
Down the road a piece, the heater couldn't heat the car. I had insulated coveralls on and a down jacket and was still cold. When I stopped at a grab & run store to get a Pepsi, I got some cardboard to put in front of the radiator and finally got some heat. Decided to drink the Pepsi later, put it in the back under the canopy and 20 minutes later when I went for it, the can was frozen solid.
I saw -17 degrees when I lived in Montana and it sure wasn't as cold then as it was that morning in Iowa.