When I set out to write Matriarch, I did so without any preset notion of how long it would be. At the time, it didn't even have a title. There was just a story to be told.
Of course, that story would turn into nine stories.
But, to the point, as I wrote each one, I just let what needed to be said flow out of me. As I did, a pattern emerged. It would be 3 parts to a full story arc. There would be 3 story arcs, or tales, told. So, 9 parts all together.
And so it went. And it worked out well.
Another pattern emerged as I worked through each part - and quite by chance. The parts were all falling between 32 and 40 pages (that's Word pages - not book sized pages).
After realizing this, I targeted that range for the remaining parts. Again, it wasn't difficult because they just seemed to wrap up themselves at that point.
Basically, I had in my head that each part was a short story. And then I realized - well, maybe more of a novelette.
To me (and I know my view is skewed as the author - and having read them so many times I've lost track) each part is a very quick read. They don't really feel like a long book.
however, when I finished (and before beginning revisions), I totaled up the pages and words. There it was: 137,000. I literally choked.
Now, revisions continue - and certainly there is some fat to be trimmed off the steak (I may have been accused of being long-winded from time to time). SO, that number will change some. Some.
In the end, though, I believe a story has to tell itself. Cut it down too far and risk suffocating the characters or an arc.
When all is said and done, I'll let the readers decide if it was too much...or not enough.