I've been the last few years in Sept. and haven't had too much trouble with free dining and crowds at eating establishments. (Although, typically, I don't eat lunch at peak times...and rarely eat dinner at peak times either.)
Wait times, for me, for lunches have been no larger than they have ever been when I go at other times.
For dinners, I also haven't noticed too much of a wait. The longest I remember was LeCellier...but it wasn't too bad either. (Although it's size would generate this more than anything. That and there was a line of people trying to get in for food who didn't have dining ressies and they were being turned away.)