Scenario – pedals simply spinning round & round, zero catch / forward motion. Get off, grab with hand & it's ok. Happened 3 times the other night, & if I free-wheel for a bit there's a few seconds delay before the drive 'engages'…?? Wondering if it's something to do with the build up of snow / slush around the bottom bracket? (b.b. is on the way out, a mm or 2 movement side-to-side)
Anyone enlighten / ridicule me?

Freehub body freezing up…..pish on it.Enlightenment.

Freewheel is freezing up.

Fool.Ridicule.
5 seconds too slow allthepipes…IN YOUR FACE LOSER!!!Slow day.

Its your freehub freezing- common when you're riding in the really-cold!
The problem I've been having is my (cable) brakes freezing solid on the cross bike, I think using Nokons is making it worse than it would be with XTR cables though.

Thanks for the words of wisdom – will make sure to add a few pre-ride lagers in my prep next time 🙂