I use wool glove liners inside Canadian military surplus wool mittens and shells. My thoughts are that the only people who know cold better than the Candians are the Russians and the Inuit. :P

Also, keep your body warm. I've found that I can get away with less on my hands if I need dexterity if I keep my chest warm, which makes sense. Your body adjusts the ammount of blood going to hands and feet to keep your torso warm, so if you keep your torso warmer, you won't have to wear the gloves. Your fingers will get cold, and AFAIK this won't do squat against frost bite, but you will at least be able to use them.