I usually wear a waterproof eVent lined jacket and similar pants over my regular clothes and maybe an insulation layer for when it gets really cold (but then I'd probably be walking, riding my regular bike, or driving if it gets bad enough).
For snow/ice, they usually take care of the streets so I think my knobby 4" tires should do great when it comes to snow and salted streets: My biggest concern is salty slush corroding things so I'll have to pay extra attention to wiping everything dry though.
A leather Jacket and thermal underwear. Not much in the way of ice here so it's really about layering for the wind.
Might want to wear some pants too, you maniac.
testicles ascend
Same as always. Insulated jumpsuit, windbreaker on top, insulated gloves, thermal head protector under my helmet.
More walking when biking is not possible, i.e. when conditions are too slippery (ice patches etc.).
When roads are dry there's no problem with biking, there's just one more layer of clothing.
Just in case you didn't know: They make spikes you can strap onto your shoes called crampons: If you get a lot of icy conditions, these things are great for avoiding slips. Has to be pretty icy for them to be worth it though.
I live in Imperial Beach, California. That is my winter riding plan, lol.