HBO refuses to comment to either confirm or deny the speculations about the “Game of Thrones” movie, obviously focusing instead on Season 6 of TV series showing next spring.
Martin was later on quoted as saying that idea of having a movie finishing the “Game of Thrones” TV series greatly appeals to the actors because it is surely one way to end with a bang.
Assuming that it is true that Martin has yet to finish writing “The Winds of Winter” at this time, then he only has until the end of the year to complete it. It is imperative that the book comes out before Season 6 of “Game of Thrones” is aired on HBO in April next year.
This means that the book needs to come out in March 2016 at the latest. Martin has to finish writing the book by November or December at the latest because it would take at least two more months to put it on publication and mass production.
If Martin will write until the end of the year to complete “The Winds of Winter,” then immediately thereafter, he should start writing the seventh book titled “A Dream of Spring,” because it would just leave him with less than a year to finish it too.