Game of Thrones is back, and gone are the simple days of “one season, one book.” The showrunners have split the third book into two seasons, and, what’s more, the show’s episodes are synchronizing less and less with chapters from the books, as the chart below, created by Reddit user JoelTone and based on data from the Game of Thrones wiki, illustrates. - Kevin (aka ThreadKilla)

They've already gotten how Martin plans on ending it. Should old boy keel over between now and then, we'll get an ending he made himself. - Akiva

HBO has officially said there will be only 7 seasons of GoT. So, given that they've already split AFFCs into two seasons and ADWDs is even longer, there's going to have to be some consolidation of the written works to fit the series length. - Kevin (aka ThreadKilla)

My guess, and I hope I’m wrong, is that they’ll have a few more seasons and then tack on a LotR-sized trilogy or so of movies to round the whole thing out. - Akiva