Series bosses Jen Statsky, Lucia Aniello, and Paul W. Downs addressed that question (among many others) as part of a round of interviews they’ve been doing this week, attached to the show’s finale. Specifically, the trio talked to Variety about their previously mentioned plans to make the show a five-season series, and why they’re not completely committed to calling season 5 the final season just yet. Here’s Downs: “We are now breaking up Season 5, and we have to see how many episodes it will take us to get to where we know we’re going to go. The final scene of the final episode has been in our minds since 2015, and we’re excited to get there. But that may take more episodes than we can fit in the season. So the truth is that we don’t know.”
The creators reiterated that same point in other conversations, including with Deadline, where Aniello noted the show’s commitment (increasingly rare in the streaming game) to getting their show out on schedule once per year. “We very much know where we want to end the series; it’s how we pitched the show originally,” Aniello confirmed. “Right now, we’re still writing towards it ending in the fifth season. But that being said, we have a lot of things we want to do this season. A lot of stories we want to pay homage to and a lot of characters we want to do right by. So that being said, there’s always a world where it’s more than the amount that we can turn out in a year. Because we really like having the show out every year. But we are really in the middle of figuring it out. If it’s not done in five, it’s close to it.”
Elsewhere in interviews, the creators say they expect to begin filming the next season in the fall; by then, they’ll presumably have the story broken down in full, and will know whether season 5 will be the show’s stopping point.