It's a pretty intense production, they're about to start production soon. I'm not sure that [Benioff and Weiss] could really wrap their heads around it when they're just about to start production [on season 7]. HBO has finally addressed a much lingering issue about 'Game of Thrones' and that surely is not pleasant for the fans.The network has confirmed on July 30 that season eight will officially be the last one, reports E! "The showrunners have also planned for the eighth season to consist of merely six episodes. It's something I'm not opposed to, but of course it has to make sense creatively.
Source: Times of India July 31, 2016 06:11 UTC