It all depends on what you call an ununited Germany. A Germany missing for example Bavaria seems reasonable. Maybe some Bavarians at first want to become part of Germany, but because of later complications decide that they aren't Germans, not unlike the Austrians. Or maybe Hanover remains in personal union with Britain and Prussia doesn't want to pick a fight with Great Britain and Hanover remains outside Germany. Those things I can see happening. Certainly as those things happened OTL. Both Austria and Luxembourg aren't part of Germany. What happened to them could happen to other parts of Germany. Because of Luxembourg and Austria (and going even further back the Netherlands, Belgium and Switserland) you could even say that OTL we don't have a united Germany.