I agree they should be fine. I made a similar mistake once, putting bottles into a garage that was too cold, and all it cost me was a bit of time. Yeast are pretty resilient creatures and, as long as you didn't freeze them, they should be able to do their job. The cold will send them dormant and they will settle to the bottom of the bottle. They will wake up when warmed, and if you want to give them a bit of extra help, you could tip each bottle upside down for a couple of seconds to help mix the yeast into the beer again.
--GF