Sometimes there is, sometimes there isn't. Sorry I can't help any more than that but I would say there's about a 25% chance that there will be. If there is then it probably won't affect the road too much. Global warming and all that.
Almost certainly not. There are probably only about 4 or 5 days per year when there is any real amount of snow, and what there is melts quickly - especially on the main roads. I reckon that 25% is a gross over-estimate.
Well I would say that there is snow on the ground between London and York at the end of December about once every 4 years.
Is there any way of finding this sort of information?