I have charged many times at a supercharger and when finished I simply press unlock on the screen and then get out of the car to remove the charger cable. Last night I couldn't unlock it that way. I tried to unlock from the phone app and that didn't work either. If you find yourself in this predicament there is an easy solution. Simply press the round button on the charger (see attached picture) and then the car will be freed! I wonder if the cold weather update created this bug?