The question is simple, at what point does it become (effectively) impossible to have a Pan-Germanic state? For the purposes of this, said state must include, at bare minimum, the Netherlands, Flanders, and all of Germany proper(as in, all German-speaking states & territories).
Bonus points for the addition of Scandinavia(all or part, with Finland being considered Scandinavian as well), England, and the various bits of the Baltic with sizable German communities, and Transylvania(obviously depending on PoD if this is Germanic-speaking or not).
Colonies of any of the formerly independent Germanic states can be kept or split off at your discretion.
Also for the purposes of this challenge, the states that are absorbed must mostly pleased, or atleast indifferent to the result. Areas can be added through conquest, but I'd prefer that be a minimum of cases.
I stress once more, the latest possible PoD.