Your DD may really be fine at your dinners with her, especially considering that you have taken her bedtime into consideration. I think it's the people that DON'T do that having all the problems. I saw a couple with 2 small children, maybe ages 2 and 4, at Raglan Road get seated after us (our ADR was for 9 PM). Kids were having full blown meltdowns before they even ordered drinks. Fortunately for us (and everyone else) the band completely drowned them out.
We have taken our kids out to eat since birth, so they have always been pretty calm in restaurants. First Disney trip with kids they were ages 7, 5 and 23 months. We did the old Dreammaker Gold plan which I think is now comparable to the platinum package. My friend (who couldn't eat at a pizza place with her then 5 year old with our him kicking people and crawling around the floor) thought I was crazy.
She told me that there was "No way" our 23 month old would behave in all those TS restaurants. She had seen my 5 and 7 year olds at restaurants and knew that they would be well-behaved, but insisted I was in for a terrible time at TS restaurants.
Our DD was absolutely fine at every single lunch and dinner of the 10 day trip. The weirdest thing was that she was most cranky at breakfasts. She was not used to being woken up in the morning for anything. If you look at the photos of our first couple character breakfasts you can see she was crying off and on. She did adapt, and by day 3 or 4 she was fine at the breakasts and even smiled for pictures.
We had a Maclaren umbrella stroller with us and some of our lunches she was asleep and the staff just let us wheel her up to the table and she slept through the lunches. This happened at Alfredos, Sci-Fi, Tonys and Rose and Crown. We would have woken her up, but these places all offered to let her keep sleeping when we were sat. Maybe they were afraid she'd start freaking out or something!
They just moved the highchair that was on our ADR's and put her umbrella stroller there. At Sci-Fi they let me put her right by the car. She was still sleeping when we left all these lunches. The lunches she was awake for were a nice break from the heat and crowds. She got to have cold milk in her sippy cup and recharge a little. I will never ever understand why someone would choose eating at a crowded CS place with the long lines, looking for a table ordeal, fix-ins bar trips, drink refills, etc. with young kids over a relaxing air conditioned TS lunch.
But that's just my opinion!
You may find that your DD does great at your TS meals. Good luck!