Spring training in North Carolina

I am on the other side of the mountain but I would recommend somewhere around Asheville. You can get a lot of good climbing from there and even get to the Boone area, where Armstrong trained, in a short time.
The weather is pretty good right now for training.
You may want to make contact with this club to get some details. abrc.netabrc.netOpen ↗

You could camp or stay in Robbinsville NC, and ride some great roads past the lakes and damns, and get climbs which cross the Applachian Trail. Deale's Gap and the "Tail of the Dragon" on hwy 129 is a big favorite of the moto crowd. Going west, you can ride up the Cherohala Skyway; a great climb for about 15 miles up to the 5350 ft summit and the border of TN.

I don't mtn bike, but nearby to the east is the famous and very popular Tsali area , 40 miles of singletrack in the Nantahala National Forest.

and if you want to come to the good side of the Mountain 🙂 I can show you some great routes.

I grew up near Boone NC and can tell you it's a great place to ride, when I lived down there the people were very bike friendly and the weather was awesome for riding in the spring. One place that's pretty nice is the blue ridge parkway, you can park at the Tanger Outlet in Blowing Rock and then ride a bit out to the parkway and hop on. There are many great places to ride but this gives you a good place to park as well.