GRRM has already written thousands of unpublished pages trying to tie up every loose end in GoT.
He will die before he completes this.
FWIW, I thought his GoT books were excellent. I didn't read them until after I had watched the series but it didn't diminish the books at all.
I should probably read this one.
“He will die before he completes this.”
Then I’ll never watch this new show. I really have no sympathy for him, he created the mess himself, and has had every opportunity to fix it, but he prefers to do other things with his time.