At what temp does red wine freeze?

[Grape Stuff]

I keep around 30 bottles in my basement and here in Seattle we've had some very chilly weather this week (teens/20s at night). I don't think there's any danger in the bottles simply being very cold, but I'm sure if they froze....well, I'd hate to find out what that would do to them. So I guess the question is how cold is too cold for short term storage? I know I shouldn't expose them to rapid changes in temp, so that's partly why I just leave them there. any toughts?