It's compulsory to change to winter tyres (stiffer rubber compound and different tread pattern) after a certain date. If you don't, and have an accident, the insurance won't pay out. There's also snow chains, but they're a bitch to use. But yeah, winter in the UK was always fun. :)

Yep, I drove back from Istanbul in winter of 1980, left in a snow blizzard on a set of second hand chains we bought in the bazar and didn't hit tarmac till after Koln. It was like driving with square wheels! I've got a set of winter tyres I keep in my local garage who charge min storage and replace