A fairly big thing was made about Cersei now being able to hire mercenaries, so they will have to be used at some point. Whether this is in a double cross against Dany's armies, or if she actually comes round and adds them to the common army to fight the WW will be the question. And if there is to be a double cross will it happen this season or next, but that mercenary army will have to be used for something before anything happens to Cersei you would have thought.