My preference as a reader is about 2k to 4k per chapter and between 6 to 15 chapters in length. But more important than chapter length, for me at least, is the steady pacing of the story and completeness in the tale. I don't mind reading 10k words in a single chapter if the pacing and development is constant. Hope that helps!

I dont go by words, more of pages. Usually i stop at 9 pages in ms word :)

Can I answer even tho I'm not a friend? ;;

It depends a little on the story. Normally I go for between 2-3k words in a chapter, especially in those stories where I started with chapters at this length. But then I have a story that has 10k word chapters - and that story has 6 chapters but is still up there as one of the longest stories I've ever written.

I say you look at the chapter and figure out if you can have a split or if it would be weird. You can easily go up to 5k without splitting as well. ^^

It's actually depends on you on how many words you want in a chapter. In my case, I set the target 3000++ in a chapter. It's a challenge for myself to see how far I can expand my plot and the details.
For epilogue, (in my opinion), as long as it's a little shorter than any other chapter will do. But if there are important details, you may have it long and it brings no harm because epilogue gives us the clearer picture of everything.

Good luck!!!