We've stayed at the KOA at Boone a couple times last year. We had our 31' TT and f250 crew cab. The first time I made reservations online. Got there and the site I was put in was similar to what you mentioned, except we had no issue with wifi. The road our site was in was rutted out some. Pulling out was a chore and we missed a tree by a couple inches. I should of not accepted the site. Shame on me.
I did notice that a couple rows over that it was nicer and the sites were bigger. The next time we went which was about a month later, I called them to make the reservations. I told them I didn't want to be out in the same area. The girl was very nice about it. And while I was on the phone went through her computer for available sites and we finally agreed on one. When I got there, I checked the site before pulling down to it. It's not a huge campground and the 5 minute walk to check the site was worth it. The site was 100% better.
We like the Boone KOA. Just some of the sites are not good. We never used the bath house. But everything else seemed ok.