You didn't mention what kind of cadence you maintain, and I don't have anything to add to what others said about staying warm. But to build a higher cadence, ride rollers. Winter's coming anyway. Do cadence intervals. 1 minute at 100 rpm, 1 minute at your normal cadence... 1 minute at 110, 1 minute at whatever's comfortable... keep going until you've reached the cadence where you're bouncing all over the place and feel like you're going to come off the rollers, then pyramid back down 10 rpm at a time. And back up and down at least one more time during your workout. You'll be smoother and pedal faster in no time.