make ADRs ASAP...you will be hot, tired, hungry and possibly out of luck without them. If you decide not to keep them call and cancel as soon as you decide.
Based on your e-mail you've already decided when you'll be hungry or eat.
Decide where you'll be (ie. park, resort, etc.) and try to find a convenient place. Here is what we did on our trip 8/30-9/4
8/30 Arrived in afternoon, no park, light late lunch at resort, special meal at 8pm at Narcoossee's at the Grand Floridian, it was our event for the day
8/31 Spent morning in MK, took monorails to Epcot for 2pm lunch, made sure we would not be rushed get to Epcot if we got side tracked at MK; turned out we were hungry sooner, showed up early and were seated right away
9/1 started the day with a buffet character breakfast, could go anywhere from there
9/2 buffet dinner close to the park we were in for the afternoon (Animal Kingdom), park closed an hour before our dinner time, so no chance of getting hung up
9/3 wanted to cancel this one as it did interfere with our park activities, but it gave us Fantasmic seating so we kept it, arrived late though
9/4 no ADRs made, used up our remaining CS credits at resort
I hope this gives you some ideas on how to gurantee you'll get a nice meal and still have some good park/resort time; also its not just a meal break, but a rest and AC break too