The opuntia ficus indica is marginally hardy in our growing zone, and it is obvious that 11 degrees does a number on it.
However, the roots are still in tact and it will probably regrow. I cleaned up the damaged pads, but left a few that had already been nibbled on by a jack rabbit. It's no wonder the animals like this cactus as the glochids are few (but certainly there), and the flesh succulent. This is the variety that the Mexicans eat as nopalitos. Now might be a good time to try some.