I just cant imagine how, if the next series is the last, it is all in a different location which means, no Bright, no Thursday, no Strange, no Pathologist.
If Morse goes off to Kiddlington(?) on 4 January will there be a totally new cast.
Joan ended it with Morse because of his lack of empathy or his ability to show it. (And in my opinion because he's a snob and always goes after arty, upper class types) Also thought the letter when he wrote too her as "Miss Thursday" indicated his respect for her as his DI's daughter but not much else.
Also, from reading a what are the links Morse, Lewis, Endeavour, the jump from the end of the next Endeavour will be 17 years, as they are basing it on when the tv series started not when the books were first published.
So a lot of time for Endeavour to become Morse.
But cant imagine a series without the other main characters.