Interesting summary of the season finale in yesterday's N.Y post on page 3. Because it appeared in yesterday's paper, it had to have been written before the show aired on Sunday night to meet the paper's print deadline. The columnist wrote that Cersei ascends to the Iron Throne while a jealous Jamie looks on. Here I differ with the columnist. As implied in my previous post, Jamie is looking on in contempt & disdain, NOT jealousy. This is a very important difference. As others have stated, Jamie killed the Mad King when he decreed that the entire populace be destroyed by wildfire. Cersei, with her actions, has betrayed the trust of her subjects & revealed herself as a tyrant. This action, which Jamie would never have approved of had he been present & would have counselled against, could be the trigger that causes a schism between the twins. With the winds of war on the horizon, (obvious with the approach of the Night King, not yet apparent to the Lannisters of Dani's approach) I think that Jamie will weigh his options. He will ride North with the Red Army, ostensibly to aid in the defense against the zombie invaders, but really to distance himself from Cersei's tyranny. After the battle against the White Walkers is won, he will ally with the Starks in the war against King's Landing.
An additional factor that leads to this conclusion is that it was Jamie who aided Tyrion in his escape after Tyrion assassinated Tywin. The brothers have a bond that Cersei never shared. Cersei has always despised Tryion & wants him slaughtered for his part in the assassination of Jeoffrey. Jamie, while decrying the loss of his eldest son, was tempered by the fact that Jeoffrey had Ned Stark slain, who Jamie admired for his honesty & courage.
Maybe I'm giving Jamie too much credit, but there is a sense of reason that he displays (e.g allowing Brienne & her squire to escape from River Run) that would NEVER be exhibited by the ruthless Cersei.