The visit in February also included Bryan Cogman, who mentioned it in a Rolling Stone
David, Dan and I just met with him over a few days at his home in Santa Fe, and it was so exhilarating to hear him talk about the mythology of Westeros and what's in store for the characters. It's going to be a hell of a lot of fun moving forward.
I imagine they get together with him at least annually to talk about what they have planned for the following season and the ways in which it might conflict with what's coming in future books.
On his Conan
appearance last night Martin said he was writing The Winds of Winter
"very fast" because he's fully aware the show might catch up. I wouldn't read too much into that, but he did seem more generally optimistic about his progress than in interviews from last year, when he was still in "it's a long way off" mode. Most of the extra projects he took on in the burst of optimism that followed finishing Dance
have been finished (or cancelled), so he may have more time to devote to the book now.