Like RemcoW said, I think the problem is that there is no power assist to your brakes. You should be able to press the brake pedal to get the car to stop, but it may require much more power–maybe even both feet depending how big and strong you are. Try pushing on the pedal really hard and see if it moves next cold morning. If so, you have a problem with the power booster or vacuum system to the booster. Whatever the case, if you are unable to safely brake the car, have it towed to a shop. Don’t drive it and risk damaging the car, you, or someone else.