Wear less. You're making the #1 winter cycling mistake, which is to bundle up. You need something that wicks next to your skin (synthetics like CoolMax, or merino wool - which is softer and doesn't get stinky, so it's worth the extra cost!), and something to protect you from wind, and not a hell of a lot else. Certainly very little insulation, since you will be producing quite a lot of heat through your efforts (bring a sweater or fleece jacket to pop on when you stop).
It's a bit of a balancing act and it's different for each person and each climate region; you'll figure out what works best for you soon enough. But a general rule of thumb is that you should feel a bit cool - not shivering-cold, but close to chilly - before you start out, and you'll warm up pretty soon. Extremities like hands and feet will get colder than your core, so it's kind of the opposite from the conventional wisdom of bundling up the torso.