The upcoming One Piece episode is covering chapter 757, which is the Sabo vs Fujitora "fight" but at the same time we don't know if it'll cover the entire chapter. Assuming it'll go on a chapter per episode pacing consistently then it'll be 27 episodes (28 if you count the episode for tmrw) but realistically it's going to be close to 35 episodes. The pacing has been so inconsistent with this arc actually. Just see for yourself how many episodes has aired for the Dressrosa arc in the anime and compare it to the number of chapters it covered thus far.
