Its pretty common. The rain freezing didn't help. Wait for the car to warm up first and drive it for a bit and then usually it opens...but if its frozen from the rain on the outside. It probably won't. When the regulator goes out..You'll know, because the window won't come back up, or it will fall down into the door and make a loud crashing noise like someone is smashing your window. The signs of a bad regulator usually are a popping or crackling kind of sound when you are putting the window up or down..thats when its time for a new one.