Ygritte
While Ygritte (Rose Leslie) died in Game of Thrones season 4 when Olly shot her with an arrow, she was the only woman that Jon Snow truly loved aside from Daenerys (which became complicated once he discovered she was his aunt). The red-haired Wildling would have a much more pronounced impact on Jon Snow as he reconnects with the free folk and explores her old home beyond the Wall, opening the door for Ygritte to return in the spinoff through flashbacks or visions. Game of Thrones largely strayed from the use of flashbacks outside of Bran’s time-traveling as the Three-Eyed Raven, but a Jon Snow spinoff could freely use this storytelling device with new showrunners. Kit Harington is also married to Rose Leslie in real life, so it would be much easier to recruit the actress to reprise her role for the Jon Snow spinoff series.
Tyrion Lannister
As the Hand of the King, Tyrion Lannister (Peter Dinklage) will be tasked with many of the responsibilities that Bran isn’t able to perform, which may include lengthy travels to Castle Black. Jon and Tyrion bade a heartfelt goodbye to one another in the Game of Thrones season 8 finale, but Tyrion mentioned that this wouldn’t be the last time they saw one another. Referencing the time the two spent together at Castle Black in Game of Thrones season 1, Tyrion explained that they’d see each other again the next time he wanted to urinate off the Wall, thus setting up a fitting cameo for the character in Jon Snow’s spinoff.