It's been some time since I went to Reno for the Air Races so I don't know if the situation is still similar, but at that time if you didn't have your Hotel/motel reservation, you would not find a place to stay. A lot of those places would start taking reservations for the next year right after the current year's races were finished.
You mention Dixie Jets; we have a President's Day Fly-In that's been going on for quite a few years now except it's not on President's Day weekend anymore but the weekend after. Reason? There are so many people in St George for that weekend, that guys who wanted to come to the fly-in could not get a room, so the event was moved back a week.
Just a thought if you're going to try and hold a Fly-In the same weekend as the Reno Races. You might want to do a bit of nosing around and see what reservation availability is for that weekend?