Thankfully, I have been able to keept the car in the garage and ride at -30. Passed a lot of cars needing a boost though.
My commute is about 20 minutes on bike. At -35 C I passed 5 cars in parking lots with the hood up and in best case jumper cables from neighbour cars. There were a lot of cars that just didn't start any more.
Times like these I wish HN had a downvote button.
At a certain karma threshold (500?) a downvote button is enabled; the desaturated/greyed out appearance of vdaea's comment indicates that people have been using it.