Do you think Bowen Marsh planned Jon’s assassination in advance, perhaps in response to the planned ranging to Hardhome, or was it a spur of the moment thing in response to Jon planning to march on Winterfell? Did Bowen Marsh have a plan to survive/escape after stabbing Jon or could the who thing be seen as an elaborate suicide?

I’ll get into this more when I get to ADWD, but it was definitely planned in advance. If you look at how Jon’s assassination went down, you don’t get that kind of Julius Caesar-style coordinated assault without prior planning, and no one knew about Jon’s planned march to Winterfell before he opened his mouth.

I believe that Marsh began planning his coup the moment Jon agreed to let the wildlings through the Wall, and I think his plan for survival was and is a coup, with either Marsh or one of his allies declaring themselves the 999th Lord Commander.