I may be a bit late, but here are my two cents...
I live just east of Charlotte and have not had any problems finding a good physician who accepts Tricare in Charlotte or farther east. Unfortunately, I can't speak for western NC. The worst case I've had was one physician who was non participating, but filed on my behalf and I had to endorse the payment to them when Tricare sent me the check, which was no biggie.
Good luck and welcome to the neighborhood