These Kombi gloves are good to -10F at any speed. Make sure the mitten or glove you choose still allows you to brake adequately though.

I bought this mitten about 7yrs ago...still holding up...price seems to have jumped but maybe you can get it cheaper elsewhere. Notice that the mittens clip together so you don't loose one. Very handy.
http://www.snowshack.com/detail/SNW+KB%2D02035+L