Nashville Prevost is certainly an option I have used many times over the years. The only drawback is their proximity to downtown. Lately however, I have also parked at the State Fairgounds. At first this looks like a sketchy location but they have 24 hour security, have 50A power, and are a 10 minute Uber ride from downtown. About 50% of the time an attendant remembers to come by and collect the $20 fee for parking there overnight. We have also parked many times at the Harris Teeter out in Belle Meade. I don’t know where your event is but thought I’d throw out some alternatives.