At least 2 posts have suggested INSULATED heated gear. I wish I had read these before my purchase.
I have an Aerostich heated jacket (not the AirVantage like SMSpiff's). I occasionally use it alone and it's a very good wind shell with some insulating capability. And the pit zips align with my shell pit zips so I can quickly ventilate when the temps warm up.
BUT about 80% of the time that I use my heated jacket I wear an insulated jacket over it. It's all very versatile, but an insulated and heated layer would be so much simpler.
"The belief that there is only one truth, and that oneself is in possession of it, is the root of all evil in the world."-- Max Born, Nobel Physicist