He told Entertainment Weekly:
I wish it was out now. Maybe I’m being overly optimistic about how quickly I can finish. But I canceled two convention appearances, I’m turning down a lot more interviews—anything I can do to clear my decks and get this done.On having started the book after releasing Book V, A Dance With Dragons, in 2011:
I was red hot on the book and I put it aside for six months. I was so into it. I was pushing so hard that I was writing very well. I should have just gone on from there, because I was so into it and it was moving so fast then. But I didn’t because I had to switch gears into the editing phase and then the book tour. The iron does cool off, for me especially.
Source: Entertainment Weekly