I remember one spell in the 1990s when between Christmas and the early part of January, Central Scotland experienced -20 °C, for quite a few days on the trot. I had to drive through from Fife to Greenock to start work after the New Year. It was a gorgeous sunny day with not a breath of wind but these sub-zero temperatures. There were cars broken down the length of the M8, one every couple of miles or so.
I had the Carlton at the time, and as soon as I tried the screenwasher, despite them having 50% Isopropan-2-ol in the solution, I realised the jets were frozen. I manage to get to the western end of the M8 but the increasing lowering sun made the screen almost opaque. I pulled into a layby and lifted the bonnet intending to get some water out of the reservoir and, despite having already covered 70 miles, and with a hot engine, it was frozen solid.
That was the winter when our American manager decided not to leave the heating on over the Christmas holidays, and the numerous burst pipes did more than £1 million pounds of damage. He left national Semiconductor a couple of weeks later.