Well there's probably only 16ish episodes left after this, right? And the possibility of another break.
If Leon/Ash and Cynthia/Ash gets 5 or 6 episodes and there's breaks between them and at least 1 episode for Leon/Diantha or Lance, and a couple of episodes for farewell, that only leaves them with, what, 5 episodes for Project Mew plus probably at least one filler?
Well, we have (assuming no breaks)
July - 116-119
August - 120-123
September - 124-128
October - 129-132
Adds up to 17 episodes. 3 of those will be battles in the first round. At least 1 for Lance/Diantha vs Leon and at least one for Ash vs Cynthia. That brings us down to 12. At least 2 for Ash vs Leon, bringing us down to 10.
Chloe is bound to get one episode of conclusion, so down to 9. Project Mew should get at least 3 episodes, so down to 6. An epilogue arc, which should be at least 2 episodes (going off past series), so we are down to 4.
So my other possibilities for episodes are:
1. Extended Epilogue
2. Filler ep
3. Extended Project Mew arc
4. Ash vs Cynthia lasting 2 eps.
5. Ash vs Leon lasting 3.
6. Extended Chloe eps
7. Another break
It's unlikely they'll extend to November.