Hi, Deadman and all.
I’m a little bit late to the game here. Just the same, I agree with everyone else here that 20k words in a multi-chapter story is a bit excessive. Sometimes, the story flow just won’t let you cut it any shorter. However, if that’s the case, then you had better have some very exciting and readable stuff. An alternative is to put more content in to the chapter, allowing you to split the now 24k chunk of prose into two 9k chapters and a 6k chapter while maintaining both story pacing and reader interest.
When looking at stories as a reader, I tend to look for longer, but not “too long” chapters. As a rule of thumb, a 2k chapter is a “Reader’s Digest story of a story,” and more than 20k has me wondering if the writer has any clue about what they’re writing. In “published life,” Theodore Dreiser’s An American Tragedy has a chapter that’s barely two pages, plus multiple chapters that are practically novellas or at least novella length in their own right.
Cheers!