Andy and I hit up Tranq Saturday night for a little night ride. It was 22 degrees when we started at about 7:20 PM from the upper PL at the ice rink and 18 degrees when we finished. We were able to get in 1.5 laps. My light ran out after a bit more than a lap, so we were relying on Andy's light, which promptly started to dim. We rode back up the hill by the apartments pretty much in the dark, but there was enough ambient light, it wasn't a big deal. The fingertips took it pretty hard the first 1/2 lap until we started generating some heat, then all was well. The frozen ground was great...gobs of traction.
Sorry, no pics...it was too cold to dig out the camera!