Technically, if you have a pass for a section, you can park there regardless of when you arrive. However, realistically, some fans (oh no!) "claim" extra spaces and are surly about giving up "their" space to later arrivals. Some of the games they have had staff "guides" that walk you down the lanes and move people out of the way so that you can reach a parking space. It's a crap shoot, but if you're wanting to park fast and can walk fast the outer lots are probably a better bet.
There's not much that's more stressful than arriving for a game about an hour before and trying to find a spot in the permit lots. Which is why I don't use them if I'm not tailgating.
That's the ONE thing that I will miss from last year. Parking was a dream.