One useful piece of info (I don't have the answer) would be to plan your service station choices carefully. We stopped at one in France on the way down and it was...adequate but a bit dirty. We'd stopped at a lovely one with a play area previously but couldn't remember where it was.
If you get early-access passes with your hotel, giving you access from 8am, it is worth getting there at 8am because you will beat the queues for the best rides for tiny ones, namely Dumbo, Teacups, Carousel, Buzz Lightyear. Once the main park opens, you can move on from those rides and do things like It's a Small World, Circus Train, etc. Do this every morning, you won't get tired of the rides, believe me!
The VIP or fast passes are worth it. The hotel gave us one per person per day and they were invaluable at busy times.
There is stuff to do besides the rides.
Use buggies to grab a very early pitch for the evening parade. Adults can take it in turns to stay with them and take the kids for ice creams whilst you wait.
For baby food, note that most restaurants don't sell it, you have to go to the baby centre or a shop to buy some, and I even found myself heating it up in the baby centre and walking back to the restaurant on a couple of occasions. Not ideal!
The rented buggies are good and worth it even for older toddlers (our DD was 4yo) because you can push them faster than they can walk and they can nap if their legs get tired.
We didn't find much to do in Walt Disney Studios other than the Disney Playhouse/Junior show and the slinky dog ride. There were other shows but we timed it wrong and there were the French versions when we went, also close to nap time.
Getting up early seems like a slog, but is worth it, and you can always nap with the kids in the afternoon or go for a swim, then head out again in the evenings.
Have fun! Our DD still talks about it daily and we went 6 months ago. We are now trying to work out how to squeeze in a trip next year!