I believe we will have fewer but still important scenes with Cersei until the Night Walker problem is solved. She will solidify her power in the south and retake Dragonstone and the Vale (since Dany and the Knights of the Vale are in the North). She might even ambush the exhausted Guardians of Life once they have ended the white walker apocalypse.
Another theory I have is that she will give birth to a dwarf child, which she will murder. And her final scene (and last one before the epilogue) is Jamie strangling her for being a monster. My guess is that Jamie will die in the same scene, completing his redemption arc.