There is a new article and Q&A with GRRM in The Atlantic.
Here's an extract:
There's no doubt that I've wrestled with this book and the complexity and size of the series, and that may be one reason why my writing has slowed down. But my intent right from the beginning was to do something huge and epic, with a cast of thousands and many different settings.
With the general construction of the books, in some ways I took the Lord of the Rings as my model. Tolkien begins very small, in the Shire with Bilbo's birthday party, and from there, the characters all accumulate. First there's Frodo and Sam, and they pick up Merry and Pippin, and then they pick up Aragorn in Bree, and they pick up the rest of the fellowship in Rivendell, but they're still altogether. But then at a certain point, they begin to go separate ways—Frodo and Sam cross the river, Merry and Pippin are captured by orcs, and Aragorn, Gimli, and Legolas are chasing them, and they continue to separate. You get this sense of everyone being together, and then the world gets bigger and bigger.
My scheme is very similar to that. We begin in Winterfell, and everyone except Daenerys is in Winterfell, even characters that don't belong there, like Tyrion. And they set off together and then they begin to split. In that sense my books are bigger than the Lord of the Rings because there are more characters and they split further apart. It has always been my intent, as with the Lord of the Rings, that eventually it would curve around and they would start moving back together. I think I'm reaching the turning point, that's starting to happen now.
Maybe I did make it too big two books ago. But I've thrown the balls in the air and I feel obligated to keep on juggling them as best I can. You can't just forget about some of the balls, you have to deal with the plot threads that you've introduced. If I can pull it all off the way I want hopefully it will be great. And if I don't, I'm sure the world will let me know.
Follow this link for the full story.