We went 3/13 to 3/18 with the DDP. Fitting in a TS meal each day is no problem at all, if you have called ahead and made ADRs. You will find yourself looking forward to being able to sit down for a little while and relax.
For instance, we scheduled first available lunch seating on days we attended an am EMH. Nice. We had some breakfast bars we brought from home to tide us over until lunch. We did this for convenience, to be able to get going early and quickly on the days that we wanted to. We easily could have gotten cereal, muffin, cinnamon roll (which are definitely big enough to share), oatmeal, etc for a snack credit. One morning, we did get the box of Entemanns donuts the night before from the gift shop to have the following am. TS for lunch was more like brunch and lasted us fine until a regular dinner time. One day, we schedule dinner at 4:10. Use your ADRs as your guide and be prepared to flow with the day around your ADRs.
I, too worried about only having two meals a day. Everyone says it because it is true, you get a lot of food on the DDP. Our joke is like this...I went to WDW, walked 12 miles a day, swam, ran to catch the bus, sweat off tons of water weight and gained 10 pounds! Some have mentioned sharing food at the TS, but I would recommend sharing food for the CS instead. There are so many CS that have share worthy meals. I think there have been threads dedicated to the topic. Your TS meal will be a ton of food, and then you could have two lighter CS meals, because you shared them, and supplement with your snacks when you need to. And btw, a lot of snacks can be shared too, depending on what you like. We love funnel cakes, and so we shared a funnel cake in MK.
And keep in mind that some snacks sound pretty significant. For instance, a cup of chili at Casey's in MK is a snack. Plan a TS breakfast, chili for later lunch, and a big CS dinner. Check out the menus on allearsnet dot com to help you plan what would be best for your family.