Luckily not much snow and ice here in the uk, but I rode all winter even in Illinois, Norway and Wisconsin when I lived there. Here in the uk the main issue is how incredibly cold it feels when it's 5C and 100% humidity. I'm still working out the clothing situation and stocking up on woollies. Other than that, I've got my bike and me decked out with lots of lights and reflectives so I ride after work despite the dark. Although today, I took advantage of a slow day at work and did my ride at lunchtime instead. May do that more often when I can.