You are going during the food and wine festival but I still wouldn't worry about making them super early unless your dining plans aren't flexible. We frequently make PSs on the day before or even the same day we want to eat and have had no problem, as long as we're willing to be somewhat flexible on the times. For example, we might call for a 12:30 PS and all they'll have is 12:15 or 12:50. On the other hand, it never hurts to go ahead and make them, if you already know when and where you want to eat.
If you are doing any character meals, I would recommend you go ahead and make them as soon as you can.