The producers said in a recent interview that their optimal vision for the show is that it'll end up running for 80 episodes over 8 seasons.
Seasons 3 and 4, which could be shot together this year, will likely adapt
Storm, some elements of
Clash that have been pushed back and some elements of
Feast that will be brought forward. Seasons 5 and 6 will likely merge the rest of
Feast,
Dance and the climatic battles from the beginning of
Winds into a single linear storyline.