“The possibilities are open. There’s a version where the two movies are cut together. There’s a version where there’s a special director’s cut of number one and a special director’s cut of number two. And I’m happy to basically work on every one of them,”
The running time of IT: Chapter 2 is 165 minutes (the directors cut would probably exceed the 3 hour mark) but Muschietti reveals that the first cut of IT: Chapter 2 was around 4 hours.
So, if there ever is a super version (it’s not confirmed that this will actually happen) of the movies there is no telling how long they would be…
Source: Dread Central