The Witcher (opens in new tab) series on Netflix is still more than a month away, so obviously we can't say yet whether it will be any good—or, maybe more accurately, whether it will be a hit with people looking to fill the low-fantasy-shaped holes in their lives. The good news is that if it is, there's lots more to come, as showrunner Lauren Hissrich told SFX magazine (via GamesRadar (opens in new tab)) that she's already mapped out stories for seven seasons.
"We don’t have a second season yet—God willing we will—but right now it’s just about, ‘How do you set up stories that really capture audiences for years at a time?’" Hissrich said. "The worst thing we could do is put all of our energies just into season one, and not be thinking about where these characters can grow to.”
She also gently warned viewers not to get too attached to anyone, because "not all" of them will survive the first season: "I can't promise you that they're very much alive," she said.
It could be that I'm reading too much into it, but both of these points seem intended to draw a line between The Witcher and Game of Thrones—fans of which would presumably be a natural fit for Henry's Big Adventures—while implicitly promising a more satisfying conclusion for viewers.
Game of Thrones famously stomped on every rake in town on its way out the door, but it was also in the very weird position of being at least a couple of novels ahead of the books it was based on. That should be less of a problem for The Witcher, which has six novels, two short story collections, and the games (and possibly more, but that's what pops quickly out of Google) to work with.
First things first, though: Season one needs to be good. It begins on December 20, and will look something like this: