I posted this as a response to a question about the play areas, but it's a good summary of what we do. My 2 year old will be 3 later this month, but she still does this routine. It's what we do (but we go fairly often) it may give you a few ideas, though.
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I take my 2 year old fairly often, I went recently where it was very cold, they had the water entirely off on one fish blue fish, and in the Curious George water play area (But it was in the 40s) The ball factory at the back of Curious George was open (And fun!) Curious George also has a small playground under a circus tent and they can still walk through the water areas even if they are off.
My daughter can ride the kid coasters (36" height requirment) here's our typicall routine if we go over. (We live about 3 miles away from the park)
Enter IOA, go to Suess Landing, Cat in the Hat first, then Carousel, One Fish, Trolley (And the quick Suess show -Oh the stories you hear) if it's on while we are there right near the bookstore) Sometimes we'll go to the "If I ran the Zoo" Play Area, which is nice, and has a small water section and a bunch of hidden activated things to do.
After that we go to Hippogriff and ride the coaster, then we either take the train to Studios or keep going.
If we keep going in Islands, we go to Camp Jurassic and ride Flyers (You need a kid to ride, and the line moves VERY slowly... It can be a bit scary for a 2 year old, but ours seems to love it.) Camp Jurassic is a time sink, they can spend a very long time there. If we move on from there, it's Me Ship The Olive next to Popeye (another play area), then Storm Force Acceleration and out.
If we go to Studios we take the Hogwarts Express and from there we go over toward Simpsons and ride Kodos and Kang Twirl and Hurl spinny ride, then head to ET (34" Height Requirement) and then do the Barney Show, Woodpecker Coaster and Curious George--which is a time sink. The indoor Barney playground is another -- and REALLY good for a two year old, and Fivel's playland also -- 2yo insists on the raft water slide if we go there.... she's fearless. Minions (Stationary seat), Animal Actors, or Shrek if time and the tired/crankiness factor allows. There are a lot of kid meet and greets, she loves the Trolls one by ET which is fairly new. It's also worth noting that there is a toddler size potty in the Barney restrooms.
Additionally Studios has family restrooms (Two in Diagon Alley, one by Mels Drive In, one by Simpsons, one by Fast/Furious, Two by Jimmy Fallon) to make diaper changes easier, Islands has none, but First Aid areas you can go next to Oasis coolers in Lost Continent and by Guest Services at the front of the park.
Finally, there is one wildcard, there are rumors that KidZone (Barney, Fivel, Curious George, Animal Actors --- but NOT ET) will shut down at the start of next year to start Super Nintendo World construction (or at some part of the attractions and area) so be aware of that. There's nothing definitive announced about that yet other than some building permit applications and strong rumors. If that does happen, you can probably go to guest services and they may compensate somehow if it was part of your plans. (Particularly if they shut it down with little to no official notice, which seems likely based on Jaws and Terminator)
