On Saturday I did a 22 mile group ride on the fatbike through slush, mud, and snow (and I probably walked the bike a good 2 miles total). It was the hardest ride of my entire life, and also probably one of the most fun and rewarding. I made a ton of mistakes and learned a bunch...
Lessons learned:
Don't pack extra (no bike lock, snow pants etc)
Don't start out warm
Do pack extra food/water (needed more food!)
Do layer clothes (and look for wool, holy shit I got damp/wet/moist)
Do learn more about tire pressure
I'm sure most people who bike in the winter know this, and I got a lot of advice, but I was fucking wrecked at the end. Mile 19 I got cramps in all 3 sets of vastus muscles in my quad (the entire front) at the same time. I brought enough water for me (and ended up sharing some with others) but didn't bring any food/energy with. I found some gatorade energy chews I had left over from summer marathon training and was ecstatic to have them.
On that note: Any winter bikers have recommendations for awesome boots? I'd prefer non-cycling-specific boots that can also work for cycling, but I might just buy a set of wolfgar from 45NRTH if they are that awesome.