I've heard it said before that the second most likely time for German unification would be the Austro-Prussian war, and that if that occurred it would be possible for them to shoehorn Austria into a Großdeutschland scenario.
To me this seems unlikely, as far as I understand the events it seems rather difficult of the Prussians to basically annex all the German speaking parts of Austria as well as the rest of the German states. Besides this, what would happen to the rest of Austria? I admit that I do not know much about the politics of the time and would greatly appreciate it if someone could explain to me that this is, indeed, plausible.