This is a photo from a ride when it wasn't snowing at all (sorry about the open-mouth shot... I couldn't breathe through my nose at that point). That's just frosty build-up on my face from my breath. Sometimes it's amazing to see all that sticks to you when you're riding in the cold. I have no scientific proof, but I think the beard helps keep me warm. Those ice flakes would be resting on my skin if I were clean shaven. Perhaps it makes it worse. I suppose the beard could just be giving that cold moist air a place to land instead of floating away into the oblivion. I'm not sure.
But the beard is here to stay. I'm no mountain man... and I certainly don't do it for the fashion. I have a beard because razors are expensive and I'm lazy. But I'll cash it in as a benefit for winter cycling.
Get out there.