From the dizzy heights of one winter's worth of experience ...
- Fresh snow was lots of fun: I used an MTB with knobblies on and it was

.. just watch out for hard packed snow on estate roads where ham-fisted cagers have been slithering out. And especially watch out that one of them doesn't slide into you.

(I got off the bike and pushed it across the road, walking along on the path there to avoid a bus that I could see was gonig to have hassles - he did, and slid straight into where I'd have been).
- The ice that the snow turned into overnight was a non-starter.
- Fog was also something that bothered me.
- Frosty days are fine. Just make sure you've got appropriate clothing on and watch out for icy patches in shaded areas and so on.
- Rain is not a problem.
- Wind is a chore, but survivable.
Think that's about it.
Edit to add: it's worth surviving "adverse" conditions just for the look on your colleague's faces when you nonchalantly say "course I did" to the inevitable, "you didn't ride in
today, did you?"