I agree, but I'd have to amend those imperialist numbers to metric in my case.
yes, I know that you're much more of a hammerer than me, but seriously, I do notice that when really cold (-20c or more) I really do seem to go slower on my commute, just to have less face skin uncomfortableness going on, and also by then my rear trigger shifter is crying uncle so I'm in 1 or 2 gears in back, and shift between the granny and mid ring when going up the overpass and or slow snow buildup.
The colder it gets, the less the legs want to work, and keeping the bike-generated windload off the fact is a good reason to slow-roll.
I haven't had an issue in a few years, but my old single-speed winter commuter had issues with the freehub pawls freezing up at temps below 0F/-18C ... that made for some 'interesting' rides (and at least one long walk), basically, I'd ride like it was a fixie to keep the pawls engaged (& swear at myself if I forgot and freewheeled).