Probably the best way to get this is the much beloved "Divided Empire" setting, where the Hapsburgs re-unite the Southern Catholic States while Sweden or Brandenburg becomes head of a Northern Protestant Empire.
A Hanover-Prussian-Dutch personal union is maybe workable in the first half of the 1700s with the right dynastic POD.
Austria is likely to become the dominant power in the rest of Germany in such a scenario if it survives the WotAS analog. Otherwise, Bavaria.
Not a very likely situation overall, but probably manageable.