I think you’re mostly right - afterall the ending being the same as GRRMs is basically confirmed, and ultimately the basic building blocks of the show ending could be made into a satisfying ending if they weren’t so damn rushed and if they had better motivations.

I do think he is still writing though, I just think the fire has gone out. He just keeps writing drafts, trashing them, starting over, repeat. I will be shocked if we ever see TWoW, and I’ll eat my shoe if we ever see aDoS. And frankly if we do see TWoW, I think it’ll be a let down, because it’s clear that GRRM is mentally checked out of the story now