It is cold in northern parts of the world. Studded tyres are awesome. If you do not have them, forgot to mount them or cannot afford to invest for your usage, I am here for you.
The number of times I have been caught out and unicycled on snow and ice is quite high. If I can do it, you can do it. Just take it easy! Oh and wear a helmet, even if you do not normally. That kind of a fall is exactly what they are for.