The one thing you have to keep in mind is this, how long will HBO actually allow GoT to continue. Because as episodes go by, it just becomes more and more expensive to produce. Hell, they may end it after 7 seasons and do a wrap up movie. No where does it say that HBO has to produce the entirety of Games of Thrones.
I am a child of the universe. I will walk gently and true
Of course I'm a creationist. I believe man created god.