Certified GKH Gardening Expert
Likely, they will recover. Just care for them as you would, usually. I am in zone 7, myself, and though they are not hardy, here, they come up in one particular spot each Spring! You would be surprised at the stress that these plants can handle.
Once it warms up some, and you see what is dead... Clip off any dead material and let it continue on as normal.
This collection of articles will articles will help you with the care of Cannas: