Sounds like a great trip you got coming up, brumski. Merlefest always has a stellar lineup. It’s a bit too big for me, but like you said, it might be perfect for you to squeeze in a bunch of music in a short visit.
If you’re out west the Telluride festival usually has an impressive lineup, is in the cool mountains, and is limited to 10,000 patrons. I like the Gettysburg festival, too. Not quite the lineup of Merlefest, but it’s Gettysburg.