WI
Friedrich Staps had managed to kill Napoleon Bonaparte?
It would be so chaotic that I can't even imagine what would happen. Napoleon is killed in Vienna, most of his army is abroad (and probably some troops could want to rake revenge against the Germans that killed their Emperor). The peace treaty wasn't signed yet, and while the Habsburgs are broken they would have no reason to give all the concession the the French and their allies now that the Emperor is dead.
IIRC Napoleon had ordered that his brother Joseph should be his heir if he had died, but I doubt that it would be followed (or even if Joseph would want such thing). Maybe France falls into civil war?