With kickoff at 11:21am, you'll have to hit Dreamland after the game. For a good spot at the walk of champions, you'll need to be in front of the stadium by at least 9:00am. If not earlier.
As for the drive, if I were you, I'd leave around 4am and take 82 out of Prattville all the way to Tuscaloosa. Either way you decide to go, when you get to 20/59, take 359 to Jack Warner Parkway and park north of the Stadium. It will make life tremendously easier if you are deciding to leave directly after the game. If you plan to stay around for a few hours after the game, if won't really matter where you park.