Season 8 will only have six episodes
As far back as April 2016, Benioff and Weiss teased plans for a shorter final season. In an effort to manage the added pressure of creating more original content (the show has far outpaced author George R.R. Martin's source material), the showrunners divvied up GoT's final lap with seven episodes for Season 7 and six for 8. That way they could keep their standards high and deliver quality episodes for fans... and, let's be real, build hype to LeBron-James-in-high-school levels.
That's shorter than seasons past (way down from the usual 10), but you won't be shortchanged. As Cunningham put it, "When you think about it, up until last season, we'd have six months to do 10 episodes, so we're [doing] way more than that for six episodes. So that obviously will translate into longer episodes."