The question is whether Benioff and Weiss' solution to the pacing problems of those two books is to condense, or to contrive more "dramatic" variant storylines to make them fill multiple seasons naturally. Their approach to the Daenerys material in season two suggests they might be open to the latter. And they have to be thinking about how to avoid catching up to the books; I imagine that taking a freer hand with adaptation of Feast
would feel preferable to making things up entirely based on the few details of Winds
Martin has shared with them.