Game of Thrones is set take its final bow in 2019, and according to HBO president Casey Bloys, that's the earliest fans will see anything from the universe on television. While it's true that the network currently has five potential spinoff shows waiting in the wings, Bloys stated the earliest any of them will be seen is a year after GoT's conclusion. Bloys indicated HBO is intent on taking its time with the spinoff, and while it may seem like its being done to torture fans, it's actually out of respect for the original series:
Should we go forward and make a pilot and [then] a series, nothing would air on HBO until at least a year after Game of Thrones ends. We want the final season of Game of Thrones, being the special event that it is [to stand on its own]. We don't want to use it to launch [a new series]. We want some separation there.
A year of separation between Game of Thrones and its spinoff sounds like a smart move business-wise, as the series' viewing statistics from last season indicate HBO will have no trouble getting viewers in the final season. It's also a highly anticipated event with high expectations, so fans will probably need some time to process its contents.
The network might be trying to spacing it out, so that the new series won't be judged against the success or failures of its predecessor. Additionally, HBO is in the business of trying to get its subscribers to continue as long as possible, so making Game of Thrones fans wait at least for a new series is a good way of keeping them on the line.
It also might be impossible to air the spinoff alongside Game of Thrones at this point anyway, as Casey Bloys comments to TVLine indicate HBO hasn't pegged down an official idea for the future series. With Game of Thrones currently in production on its final season and no news on HBO shooting a pilot for any of the spinoffs, it would be a tall order to have a series the quality of GoT ready by 2019. With that said, one would imagine HBO needs to make a decision on which spinoff idea to pursue before the end of 2018, if the network were to air something by 2020. But again, this is all speculation at this point.
One shouldn't expect HBO to push the deadline for any spinoff related to Game of Thrones, as the network was more than willing to give the original series all the time it needs for its conclusion. Whether or not the network will grant the same timetable for a spinoff remains to be seen, but one would imagine HBO is interested in keeping the franchise's record of strong quality alive, even at the risk of pissing off fans with long delays. Ultimately, fans should just hope the wait isn't too long, or better yet, that this future spinoff worth the wait.
Game of Thrones returns to HBO in 2019. For some new television to watch in the meantime, head over to our midseason premiere guide.