User blog comment:Negiiz/What DLC would you like for Skyrim?/@comment-402843-20120424211929

They should have a DLC where after you finish the Civil War quest, the opposing side regroups and retakes some of the holds. You then must go into the actual cities and fight it out, like the Battle for Whiterun.

Or, there could be a DLC where the enemy faction appears to be returning, but upon closer inspection, the enemies are actuall Thalmor in disguise. Then the Thalmor attack Skyrim.