I don't notice it when I'm riding so much, but once I come into a warm room after being chilled it becomes a priority. I drink a lot less on rides when the temps are 30s - 50s F than I do at 70+ degrees so maybe that makes a difference. I dress in bike shorts, maybe a base layer, and windproof runners pants (Sport Hill) with two to four layers from the waist up depending on conditions and don't have a problem making a pit stop. OP, what are you wearing that makes answering the call so much more difficult in the winter than in the summer?