Just a few years ago he was saying Fire & Blood wouldn't be released until AFTER Winds. Now the first part will almost certainly release before Winds next year lol. It's almost like he needs a book out before the show ends, and since it probably won't be Winds "here you go, Fire & Blood Part 1."
He's juggling 4-6 projects at all times, running a theater, doing cons, etc. I agree he's a slow writer but the bigger problem is his time is constantly being eaten up by other things. So when he starts struggling with the story, he simply doesn't have the time to work it out. The stopping and starting and pausing and starting again simply is not working.