Originally Posted by Hypno Toad

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).