This was my first bike commute in about a year and a half. It was 20F and I was worried about the cold, but I bundled up and actually stayed warm. My water bottle was frozen solid by the time I got to work though. Had my chain fall off twice but got it back on both times and just used my back gears until I get it adjusted this weekend. Also got a flat on my front tire. Luckily, I was riding with my friend who tours and he was well prepared with a pump. I never had a pressure gauge on my pump at home so I've always just eyed it. Wow, what a difference it makes! Once it was up to full pressure, I was off and gliding down the road no problem. I'm going out to invest in a pressure gauge today.
It was a nice ride of about 8 miles despite the mechanical hiccups.