@Yirkl I wanted to check back in with you. I heard from the race organizers and they sent me this message about camping at the event:
"We have been trying to find some folks to manage the camping area. We hope to hear a final word at the beginning of the week. We'll let everyone know at that time. It is possible that we won't be able to finalize something, in which case we won't be able to have camping, so keep that in mind with your planning. We apologize for the delay in getting this settled."
It looks like there are a couple of other camping options in the vicinity of Dahlonega:
Etowah River Campground (No website, only a Facebook page)
Amicalola State Park (Website Here)
I hope you have a great time at Trails Fest!