In my piece, I made some comments about Cordwainer Smith and endings that I think I can amplify here without stealing any thunder from the forthcoming project. Essentially, the point I want to make is this: the completion of the written narrative — ie, the manuscript — is only coincidental to the completion of the story arc. That's generally how we like to do things in the Western story telling tradition, but it ain't necessarily so.
Cordwainer Smith had a habit of using a Chinese narrative style in which the opening of the story handed you the completion of the arc. Or to use a different example, almost no one ever goes to see a production of Hamlet or Oedipus Rex expecting to be surprised by the ending. We already know what is going to happen, we're there to experience the narrative.
In other words, it's worth considering that notion the ending is about how the reader's journey through the story plays out, not about how the character's journey through the story plays out. The next time you're stuck on an ending, sparate the manuscript experience from the story, and see what that tells you.