Some people think of a novel and a movie version as at least roughly equivalent, at least from the perspective of the story. Yes, a novel allows internal perceptions from the characters in a way difficult for a movie, and movies concentrate on visual tools more than language, but nonetheless, the stories and characters are at least recognizably related.
Others have a different view, one which I agree with. They maintain that the more appropriate match is to a season of a quality television show, in that newish long form that cable television has been cultivating for the last few years. In other words, a season of Game of Thrones is more similar to a book in that series than any movie could be.
I think this is true for several reasons. Most obviously, the time it takes to watch, say, 13 episodes is more closely equivalent to the time spent to read a long novel, and thus characters and plots can develop to a similar depth of complexity.
But there's another feature which isn't much discussed. For a reader, reading the novel and watching the entire season of a show in a marathon are a good match. For a writer, however, a better match to the novel is the full season viewed over time. The 3+ months of the episodes, one per week, is much closer to the time it takes to write the book. Here I am not speaking specifically of George R. R. Martin who is notoriously taking a very long time between his sequels, but of myself.