George R.R. Martin Finally Delivers Good News About 'The Winds of Winter' : Martin confirmed that he’s roughly 75% finished with the long-anticipated sixth installment. At the moment, he’s penned about 1,200 pages — with another 400 to 500 still to go.

https://collider.com/the-winds-of-winter-book-length-good-news-george-rr-martin/