My coldest ever was around -25F but gears would not shift anymore. This year I have had just -1F, mild year so far and were just getting over a thaw right now. Predicted to go back into the 20's tonight and tomorrow. Still mild. I may add an extra shirt of dry wicking material for the below 0 stuff but not much more than maybe two of those under a cycling jacket. Any more than that and I start to sweat which your worst enemy in these conditions. Feet, Hands, Face is what needs special attention.