Welcome, Jame223! I'm at 6,000 feet up here in central Wyoming. Plants will survive some frostbite, but too much is lethal. Watch and wait. If the plants don't die within three or four days of being frozen, you should be fine. Even two or three undamaged leaves will be enough to bring many plants back to life.
Once I had all of my tomato plants wiped out by hail. They didn't have but a few scraggly leaves left on 'em. I was too depressed to yank them, so I left them alone. Within a month, they were thick with foliage again and producing their first fruit. Surprised the heck out of me!
IMO, there's really nothing you can do to bring back one that is severely damaged. As far as yield goes, prune off the dead leaves once they get crispy (definitely dead). I don't know whether or not that helps the plant, but it will definitely help your perception of the plant
Then again, it will assist the inner leaves, generally the last to freeze, in obtaining the necessary sun.
In the long run, the start you gave them will determine how well they do for you. If grown in rich. well-balanced soil with a satiny texture, they will give you their best.