The question starts at around 12:05. Apparently GRRM has been planning the same ending since 1991. However it is only the "broad strokes" and some small details will be different.  From reading his 1993 original outline, we can speculate a bit on how the story was supposed to end back then.  Some key quotes from the outline: It's clear to me that Dany, Tyrion, Arya, Bran, and Jon are all still surviving until the last book. They are "key players" and will obviously  have a