Cryptomeria is a good suggestion, if available. My 20-year old is ~25 feet tall, has gone through +15F to 110F. Cold temperatures enhance winter bronzing. Does not like to be crowded.
My cryptomeria survived 5F without any damage
What about yalls native White Cypress Pine?
Does it get too big for your location?
Do yall have our US native Mississippi southern Magnolia? Very beautiful small tree with big green leaves it should stay evergreen for you as it does in northern Mississippi.
Here is a decent picture of the Mississippi Southern Magnolia, they are common in Mississippi where it gets 5F even colder. And are a smaller tree. In your drier mountain location they will probably stay smaller than in the humid lowlands of Mississippi but even there they are usually around a 20 to 30 ft tall bush tree sort of lile this pic:
Yes, they’re also good in zone 6. but the shape is pyramidal
There’s several pines that grow in the Southeast
Quick growing and evergreen.
Burford Holly - 12 to 15ft. Long lasting red or yellow berries.