Why?
Taking Belgium and the Dutch Netherlands makes sense, but that much France.
What the hell?
Yeeeees... I do not see it working with the Dutch Netherlands.
Why?
Taking Belgium and the Dutch Netherlands makes sense, but that much France.
What the hell?
(...)
Even that would be ASB-territory, actually. Not only there's no way UK would accept Germany clientelizing the hell out of these countries, but no way it get accepted by any french government meaning the war gets long, costly and bogged down (the very opposite of what Bismarck excepted) while destroying all the diplomatical advantage Bismarck managed to, skillfully, get for this war.
Which, all respect due to the OP, may not be the most fitting scale of plausibilityPerhaps moving into ASB, but IMHO still more likely than the proposal made in the OP.
Bismarck never gave too much attention to colonies, as Prussian military elites at this point. It would mainly have been for punishing France, and wouldn't have allowed the colonial diversion Bismarck hoped that the country would went into.Hence I also wrote the last sentence you didn't quote, more likely any more punishing treaty (OTL Frankfurt) might also have included some colonies in addition to Alsace-Lorraine and the reparations like IOTL.