No. of Recommendations: 2
Put still another way, real life doesn't follow narrative structure. It doesn't come to a climax followed by a denouement. Once you've made the decision to have your characters ignore narrative structure, you can't stick to that if you want the story of your world to have narrative structure. You can do that for a single character, but not the world as a whole.
Sure. I get that. Life is a continuous stream of multiple characters. Some die along the way (either naturally or otherwise), offspring continue, other people continue.
He just needs to find a single resolution. Just picking an event at random: when Tyrion attains power (which he never really wanted). Maybe end there. Or end with the demise of the White Walkers. I haven't read the books, so I'm not sure how far into the TV series he has written. But you let the audience fill in the aftermath (lots of movies and books do that). They don't SHOW you what happens next, you just spend the next few weeks debating about it with your friends.