A few years back, 2011 I think, we had the coldest day that I can ever recall, I had to leave home at 05:30 to get to Birmingham airport for a flight. Cleared all the windows, sprayed de-icer etcetera but the doors refused to open because the windows were completely welded closed with ice. Thought about the warm water trick but the temperature differential would have been huge so as a last resort I operated the hood mechanism such that it un-sealed the windows and then I could get in the car.
It was -17 C
The roof didn't close fully afterwards so it was a tad drafty, but after an hour I stopped and closed it properly and there was absolutely no damage and I had no issues afterwards for the whole time I owned the car.
