Over the last 6 or 7 decades of living above the 45th parallel and keeping half a dozen cars on the road, simultaneously, I’ve dealt with my share of airing up tires in the cold, well below zero at times.
What are my tips? Do the same thing as you do when it isn’t extremely cold, but while freezing your keaster off! (You do need to check and be sure the Schrader valves in the valve stems seat properly to be sure ice doesn’t form from putting air in during ridiculous weather and hold them open a bit.)
Here’s the best tip… Redefine "Extreme Cold".
My old definition was temperatures well below zero degrees, Fahrenheit.
My new definition of "Extreme Cold" is temperatures below 70 degrees, Fahrenheit.
In a few weeks I’ll point the old Grand Prix south and drive 1,500 miles to the “winter” residence where it’s always Endless Summer!
CSA