I went with almost 3 year old twins in June 2016. We stayed at AoA. We had a car, but MK was the bus. Neither breaks at the resort or naps in stroller worked for us.
The worst day was when I did a half day at MK, then we went back to rest, then we had to get back to Ohana for dinner. I found out that dinner ADRs did not work unless we had slept in and stayed at the resort in the morning because I couldn't predict how long they needed to nap (longer than I thought, it was a nightmare waking them to get ready for dinner, but I didn't want to lose $50 and their behavior at dinner wasn't awesome so we didn't get to enjoy dinner).
And one of mine would nap in stroller while the other really had a hard time and kept getting woken up and both did not get well rested, so they didn't enjoy the evening anyhow.
I learned my lesson and planned differently for my almost 4 year old twins in June 2017.
5-6 hours of doing something in the parks was enough for us each day in the heat for 8-9 days. Yes, we did not get to see/do everything, but it was enough.
We did early wake up, breakfast in room, rope drop/EMH , use one FP until really late character breakfast or TS lunch (brunch or lunch would be our ADR), use next two FP, go back to resort, and then bathed, and rested, enjoyed resort, used pool, ate quick service/leftovers/microwave dinner, watched Disney channel on tv, visited arcade (kids loved this), play with the toys they got as souvenirs and time for bed
OR we did sleep in late, breakfast in room, pool, resort quick service/lunch in room, short nap (since we slept in), leave for parks around 2 or 3, use FP+, dinner ADR, nighttime show (Fantasmic, etc.)
We also have an older son and we did each get to spend time doing something special with him (one night after an early wake up day, my older son and I did the star wars dessert party and late EMH at Hollywood Studios while DH and the twins played in arcade and went to bed early....while another day my older DS and DH went fishing in world Showcase while I took the twins to breakfast at Akershus)