Not sure about in a container, but in the ground, they can recover when frozen down to the ground. Don't prune the dead branches away until the new growth is well under way. Just keep it watered and maybe give it a little 1/2 strength Miracle Gro or some organic fertilizer. It probably won't come back until it gets a bit warmer. Good luck!

Mine are in ground, I pruned them back at least a month ago and they have been putting out lots of new growth, but the most has been in the past couple of weeks (more rain and time change I am guessing)

They were the most frost biten I had ever seen them, I am happy to see they are coming back.

Good Luck!