Bobby-
As the supps state, part of the parking reservation process will be indicating when you plan to arrive and depart. RA (who coordinates the parking) may need to adjust things accordingly to minimize the risk of what you are talking about. Also, once the event starts, there may need to be designated times that rigs can come in. Leaving could also be an issue, but frankly, we've had people leaving from Friday - on for years.
Some locations are more difficult than others. I don't think that anyone thinks that it won't be a bit challenging, but RA feels confident they can handle it and everyone needs to work together a bit in the process.
Eric