The freezing isn't the problem. Dry freezing is a good way to store seeds.
But if there's ice at the bottom of the bottle, it sounds like there was some water there (dry glass wouldn't have ice). If the seeds got wet, they may not be good any more.
When they thaw out, I would make sure they are dry and then put them back in freezer or frig until you are ready to use them. Only way to tell for sure if they are still viable is to plant them!