except that Gneisenau had got his will and started a Prussian retreat towards Berlin, while Wellington would have moved to Antwerpen and set sail for old Blighty, waiting there for his Peninsula veterans to arrive, and to bring them back to the continent.
But you people should pay attention to what I already wrote about Napoleon's plans: To go down with a big bang, and not just fade away. When you say Napoleon, you also say Waterloo.
And that's exactly the point - if all went wrong, Wellington would have most likely moved northward to the sea while the remains of Bluchers' army would have retreated to the east in order to unite with the other parts of Prussias army (ever wondered why there were no guard units among Bluchers troops?) and then wait for the Austrians and Russians to arrive.
At the end, Napoleon would have had to fight off an army of several hundred thousand men while having the Brits in his back - same as back in 1813/14. Most presumably with the same result.
In other words: if Napoleon had won the battle of Waterloo, it would - in the end - not have made any difference.