Killing frost is killing frost everywhere I think. Same thing. Freezes all the tender stuff. Ginseng seems to be somewhat hardy, but not completely. I don't like to see frost after it comes up. I had a couple small 2s up the other night when we got that cold spell and I think they might have taken a slight hit. I think it depends on how far along they are. The seed shortage last year was the result of that late May frost you spoke of. It killed all the seed heads in the middle of the fields.
Ginseng under shade or in the woods shouldn't have been in as much danger.
...and no...it doesn't affect the roots from my experience.
Thanks to all of you for your input. That combined has said a heck of a lot. I checked yesterday and nothing up but some seal, and other companions. Lotsa rattlesnake fern (seng pointer) popping up. Fingers crossed!