I'm convinced he has draft versions of the complete story at this point and will keep revising it till he passes away whereupon it'll be published posthumously.
From what I've read about his process the initial drafts will vary massively from the finished product because he's very iterative and will go on long digressions either getting characters to a point or exploring where characters would go from where they are at that particular point.
That's what gives them such a rich feeling because he's working with characters and how they'd perhaps operate in the world but that makes it hard to wrangle them into particular positions if you're dedicated to the idea that they should proceed naturally from where they are to where they are next. It leads to a bit of a combinatorial explosion of needing to setup causes to push them into the next part of the story but you have to setup those causes first, which need their own antecedents, and on and on and on.
That's what gives them such a rich feeling because he's working with characters and how they'd perhaps operate in the world but that makes it hard to wrangle them into particular positions if you're dedicated to the idea that they should proceed naturally from where they are to where they are next. It leads to a bit of a combinatorial explosion of needing to setup causes to push them into the next part of the story but you have to setup those causes first, which need their own antecedents, and on and on and on.