I agree with Lorax. You'll be fine. Arrive as early as you can Thursday and get in line at Bohn Park. The parade starts at 6pm. You'll drive in, it's kind of a loop in the main campground, cruise around until you see what looks like a good spot, pull over, throw down a tarp to claim your spot, then unload your stuff. It will seem like chaos, but in a fun way. Then drive back to Bohn and park, and walk back or take the shuttle. Then setup. Then pop the top of your favorite beverage, and sit down in a camp chair, and watch the late-comers setting up.
Also, since you don't have a vehicle pass, you can camp backstage. It's a much smaller area, but I'd say if your number in line is 200 or less, maybe 250 or less, you can get a good spot back there. When you enter Planet Bluegrass, stay on the gravel road that runs parallel to the highway and go til it ends alongside the stage. The PB folks will direct you to a parking space. Then grab a tarp, stake out a spot, and come back and unload your stuff. Then move your car back to Bohn. The difference is that you will have to carry your stuff farther than the main campground.
Some folks prefer the main campground and some prefer backstage. You'll have a good time at either.
Listening to:
Lucinda Williams "The Ghosts of Highway 20"
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