“Are they still planning two more seasons after this one? At the current pace, one more would more than suffice.”
Yes, they are definitely signed up for season 7, and plan to wrap up in season 8. But, they are talking about making those seasons even shorter (to string out this cash cow) - only 7 and 6 episodes each, so only 13 more episodes after this season. I anticipate more deaths will occur...
The TV show has a history of picking up the pace of the story (stories) toward the end of each season. Screenwriters use a technique called a beat sheet to template out the storyline. Typically in Game of Thrones, the second half of the season advances the various stories about twice as fast as the first half of the season.
The names of the remaining season 6 episodes have been leaked:
607: The Broken Man (the Hound?, Loris?, Benjin?, Sam?)
608: No one (Arya)
609: Battle of Bastards (Jon and Ramsey)
610: The Winds of Winter (The Night’s King?)
“...making those seasons even shorter (to string out this cash cow) - only 7 and 6 episodes each...”
Hmmm...I heard just the opposite - that the next two seasons would be extended to ~13 episodes EACH...