Shells can be just as warm as insulated, with the flexibility to remove insulation once it gets warm. Where i snowboard in Japan, it doesnt get crazy cold, maybe -10 degrees (c) or so (plus windchill), but even then i have been fine with just a Uniqlo heat-tech longsleeve, and a t-shirt under my shell jacket (DC Spectrum). I run fairly hot, but if you are cold in that, add a fleece under it and you would be fine i guess.
Mind you, i doubt that your wear will have any effect on your ability to spin/air. At least not unless you are so cold/hot that you cant concentrate!