Most likely you should be fine. I should warn you though that we did Garden Grille for our CP package last year. We had the first CP seating of the night, so we ate after the show. When we got to GG, the waiting area was packed. It was the first night of CP, and somehow there were too many PSs or they had accepted too many walk-ups. Anyway, some of the people we talked to had PSs and had been waiting for over an hour. We had been told to expect a long wait, but we sat down in less than 45 minutes. (I think it was closer to 30.)
The good thing about GG is that the food is easy to serve, even if you are seated late. I'm sure if you mentioned to the person seating people and to your server that you had tickets for CP, they would try to get you moving as quickly as possible, even if there was a bit of a wait.