Waiting for the last day to call for all your PS's can work if you aren't going during a holiday or in season and if you're flexible with the dining times. If you are looking to eat at specific times I wouldn't wait until the last day as some of the more popular restaurants do fill up fast during peak dining times. We usually go when it's quite busy (holidays, and all the kids are off) and since I waited a little longer this time I didn't get the times I wanted and had to switch our schedule around.
Planning is half the fun while you're waiting for the vacation to start. Any special restaurants you're looking to try? Enjoy!