I don’t think we can tell. I think it would be different in each town. I think it would depend on which park the main campground uses and each town’s parking policies. I assume that the main campground in Des Moines will be somewhere in Waterworks Park, but which part? It looks like there is parking for about 100 cars a stone’s throw from the amphitheater, and maybe 100 more near the water works building. That may be employee parking though. These parking areas may be restricted, or first come first served.
It seemed like last year some overnight town maps didn’t come out until two weeks before the event. That will tell us where the campgrounds will be, but available parking may still be a guess. Sorry that I’m not much help.

They usually restrict parking close to the events and a few areas like around the baggage trucks. The other parking is usually a first come first get the spot. There will have designated spots but there are also several people that will grab a spot on a street a block or two away as long as there are no “no parking” signs. With a larger anticipated crowd and larger towns, it may be a little more controlled this year. It seems like every year is a bit different. The bottom line is almost always, the early your driver gets there the better spot they will have.

We have never had an issue parking very close to where we camp. We also tend to avoid the main campground if we can. We bring along one of those foldable sports wagons to help haul our stuff back and forth from the car.

Also, main camp is quite big, so you could be parked right next to it, yet still have a long hike to your spot within it.