When I lived in Nebraska, I rode to school at -20F. I had the clothing for it but the bike was pretty stiff. Wasn't a fast ride, and because my wool cap wasn't quite long enough I got frostbite on my earlobes.

Now I live in southern California. In winter it can be around 32F, which I would have laughed at in the Nebraska days but after 25 years of de-acclimitization, feels cold.