Did the foliage wilt, or does it look normal? If it looks normal, I would say they'll be fine.

Here is a link that might be useful: my potatoes and garden

Long as the roots didn't freeze, they'll be fine. The top growth may wilt and die, but if the roots stayed warm they'll just send up new shoots soon to replace them.

The tops of all my potatoes were frozen/frosted into a horrible mass of "dead worm" looking mess a while back. Left them alone and within a short length of time, there was new growth and they are now about 6" tall and very healthy. Both the whites and the Yukon God are thick and beautiful. Give them some time to come back.