Jon Snow's Immortality Theory makes GOT Spinoff better

A Game of Thrones theory about Jon Snow's immortality can solve timeline concerns regarding Jon Snow's spinoff.

HBO is currently developing a Game of Thrones series about Jon Snow. Kit Harington will reprise his role as the former King of the North. 

Jon Snow's series will be the first to follow Game of Thrones' timeline. House of the Dragon and other HBO spinoffs were already prequels.

Although Game of Thrones' Jon Snow spinoff story is still to be confirmed by Game of Thrones,

the series has the benefit of George R.R. author of A Song of Ice and Fire. 

Martin's involvement. The series won't have any book sources to help it. 

Instead, it will be heavily relying on Jon Snow's story arc, Martin's knowledge of the universe and Harington's extensive knowledge of his character. 

Jon Snow's spinoff will need to answer the question of when it will start. 

One fan theory (via Reddit), suggests that the Game of Thrones sequel series might be set in the future, if Jon is truly immortal.