Given that the author hasn't even started writing the last book in the series yet, no, no-one has.
Poor GRRM can't do anything without his worst fans jumping on him to "Finish Winds of Winter". Having seen how poor the past few seasons have been without any source material to adapt, I think it's better for him to take his time than to rush the final 2 books. Then again he has been working on TWoW for 8 years and at some point you start to wonder...