I think you are right, they will want to show the Tyrells and Cersei and Varys etc, King's landing will likely get a bit of focus as quite a few characters are there which is why I don't think they will go back to Sansa this year, she doesn't have much to do. Also leaving Jon in jail and not getting to the lord commander election would free up some more time for that. As for Bran I don't know what they could even do for him..I thought I read somewhere that Coldhands wasn't cast this season and iirc that is where he should show up next so who knows? Unless they just have a black clothed guy show up at the last second and say something like "Ive been expecting you" but don't show his face or anything? Hard to say.

edit: Just saw the preview for the finale, apparently they will show us Bran and Jon so...I know nothing haha