DS and I were going to go in July and had free dining. Now something has come up and I had to change trip back to August. Good new is we got a preferred room at ASMovies which is what we originally wanted, but ASMovies didn’t have the free dining so we had settled for ASMusic. Now we are back to ASMovies. Bad news is if we get the dining plan, the trip in August will cost us an extra $400 for the food. For the first time I’m contemplating going without the dining plan and just eating whenever we’re actually hungry. I’ll make a PPO ADR at Garden Grill and also one for PPO at BOG, but other than that we just might wing it. Winging it makes me nervous! Any helpful tips/tricks/thoughts for eating on the fly? DS will be 11 and is more interested in rides now than character meals and meet and greets, so there’s that.
We don’t generally do TS, so we always wing it…but you don’t have to totally wing it. Plan which QS (or additional TS) places you might want to do in each park, and which you don’t. Look up the menus ahead of time to help decide.
The nice thing about doing QS, if you aren’t a foodie (which we’re not) is that you aren’t locked into a time and can adjust easily,.
Definitely not foodies here. 
. As long as we have access to salads, fruits, and basic food such as chicken and burgers, etc., we’ll be fine. I know in August it will be unbelievably hot which tends to lower the appetite anyway. Last year when we went in summer we took advantage of free ice water at QS places and added Gatorade/lemonade mix to our waters.
I’m a huge fan of eating breakfast in the room! We use Garden Grocer and order breakfast stuff - protein bars, pastries, oatmeal in a cup (use the coffee maker in the room to heat up water), and my absolutely favorite morning breakfast item - pop tarts!
We make very few dining reservations (in our August 8 day trip, we’ll make only 4!). It gives us a ton of flexibility. I’ve found that you can make same day reservations if the mood strikes you fairly easily at Epcot and Magic Kingdom (assuming you aren’t trying for CRT or BOG).
I was surprised how amazing the food was at Satu’li Canteen and I’m looking forward to trying the Galaxy’s Edge QS restaurants at HS.
The breakfast of champions! 
There are some really good quick service restaurants at the parks.
My favorites: Columbia harbor House (MK), Satu’li (AK), Docking bay 7 (DHS), Epcot suffers from to many good options.
It is also fun that if you feel like you need a small break from the park you can go to a nearby resort (CBR by Skyliner or boardwalk by boat for DHS/Epcot), monorail resorts for MK. I needed a small break from MK and lunch at Captain Cook was affordable and pleasant.
Great idea about the resorts!