When I saw toe cramps I immediately thought that you might have the cleats on your shoes attached too far forward, so that you pedal too much on your toes. Don't know why they'd come when you push off from the ground, maybe they're tired and cramp under a sudden pressure, but you might want to try moving your cleats back a bit.
(I only know spd cleats btw, not road, but I'm guessing they can be adjusted a bit too)
Winter riding is much less about badassery and much more about bundle-uppery. - malkin
1995 Kona Cinder Cone commuterFrankenbike/Selle Italia SLR Lady Gel Flow
2008 white Nakamura Summit Custom mtb/Terry Falcon X
2000 Schwinn Fastback Comp road bike/Specialized Jett