my experience from riding in snow (all winter going on 3 this year, even in the 1.5-2ft dump we got) my 23 gatorskins were best for cutting through the snow.
dont ride the first major dump if you can avoid it (drivers aren't use to the snow yet and drive too fast).
Dont skid if there are cars anywhere in sight. Skids are fun but scaring the drivers of cars isnt smart, especially when they cant stop fast.
ICE, not so bad really, here are my rules. Dont turn, dont stop, keep going at the same pace. just like when you ride over garbage goop, or oil, or a dropped sandwhich, or banana peel, if you ride straight your good.
the skinny tires are amazing for the powder (as kemmer says) i run them all winter because im lazy. they are amazing for the powder snow, and ice isnt so bad once you get the hang of it and know where too ride (salted roads).
and just ride slow and dont do anything too stupid.
and crashes happen, learn to fall (into snow banks not traffic). Or don't ride, not to be mean, but dont ride like a prick and end up under a car (or snow plow)