Our family learned our lesson on the last trip. We didn't book CM, and the kids kept asking when we were going! DH and I decided to give it a break that trip. We couldn't get in at all during our vacation. Le Cellier has been like that for a while now. A few years ago we were waiting for our table outiside since it was such a nice night, and as people walkd up to the podium, the CM informed guests the place was sold out for the night. This was about 5pm.
Now I make my ADRs as soon as I can. It's a pain 6 months out, but better safe than sorry.