Hello Joe. I have been living in the Piedmont area for over 30 years and the only place that I know of is the Bar-S-Ranch. They are closed for the season. I am sure there might be some private homes that have get together but I am not aware of them. Hopefully someone will reach out to you with something. I have a couple of friends in the area but e do not have get togethers. Never really thought about it. Good luck!
As Jerseygirl point out. Bar-S Ranch is the closest to the Triad. Any other places requires a few hours of driving.
I have been in all the resort in NC, SC, and VA. My favorite is White tail resort in VA, and I love it.
Wife also like it, but she is not a big fan of public nudity. So, we normally goes to the lake and do skinny dipping in our boat.