Brent, how did it go with Dine& Play before? I know what it is and hope to use it with our two girls. Were you able to keep the kids up long enough? Do you get them a snack in the late afternoon?
I don't recall ever making a specific food run to tide them over, they more or less grazed on pizza whenever they wanted, so holding them over until late dining was not an issue for us.
I think it really depends on the individual kids and their routines. We're pretty chaotic...DD is homeschooled, so she may have dinner at 5 tonight, DS and I are going to Cub Scouts, so he will be lucky to get McDonalds in the car by 8:30.. and tomorrow those times may be reversed. :/
On our first cruise we did main dining and would lose our DS during the late show, ending up carrying a sleeper back to the room. It was a bummer to know he missed all those great shows. Many other kids wouldn't think of falling asleep during the shows, though.
Second cruise was our test run for late dining and it worked very well for us. They stayed awake during for the early show. Keeping them awake until late seating was easy for us, given a stop at the gift store or a line for pictures usually awaited us after the show. Once seated, their food would arrive almost immediately. By the time we were getting into our main course, they were becoming restless and our heros in the yellow shirts would swoop in for the rescue.
We enjoyed more dinners as a couple on that cruise than we have since! We would check on the kids throughout the evening, but they always opted to stay in the club until closing, allowing us to enjoy some nightlife activities. Typically at club closing, our 6yo was asleep on a bean bag among some other sleepers, and our (then) 8yo was still bouncing off the walls with the rest of the ADHD crowd.
I hope this helps. Dine&Play is really great for us, but would be an outright disaster for my SIL who has her kids on a fixed routine...dinner at 8 would never work for them...Good luck!