Can I throw out a strange alternative? What if, instead of doing a full day at MK, you did the Villains after hours party? I know it seems illogical to spend another full park ticket, but at the same time, you get more chances to do RotR, and if you get it your first try, you can check out Animal Kingdom or EPCOT sunday instead.
From what I've read, Disney After Hours, with it being a very limited event, the crowds are way down with short lines for a majority of the rides. Some people claim, even with only 3 hours, getting to ride 15-20 rides. That's way more than you can do spending the full day there sometimes.
https://disneyworld.disney.go.com/events-tours/magic-kingdom/disney-villains-after-hours/