That is raw idea now (coalescence of my various ideas for post-Napoleonic Europe) with main changes concentrated around lives of Napoleon Bonaparte and Alaxender I Romanov (two emperors from the title). But before expanding it into something more seriuous I'd like to ask you about plausibility of that ideas (which, I'm aware about this, isn't very high, but OTL from different TL perspective also would not be IMHO).
So let's start with Alexander's personal life, especially his marriage with Louise of Baden, which is much happier ITTL, and more fruitful. But that would play a role much later. Serious political changes starts in 1814. Polish-Saxon crisis escalates to war, as Alexander could not reach compromise with other powers. Russia and Prussia fight against coalition of Austria, France and UK. Not for long-Napoleon's escape from Elbe is delayed ITTL (Nappy fell ill and need to recover before he eventually escapes) that is one of the reasons why escalation of conflict between victorious powers is even possible. France is soon out of war, after Nappy returns to the throne (that is fun idea that he suddenly finds himself on the same side of conflicf as Alexander ) . In such circumstances Austria could not do anything better than ask for peace. Restored French Empire may become part of Europe's geopolitical landscape, while Russo-Prussian coalition achieves its goals: Prussia gets whole Saxony, Alexander gets whole Duchy of Warsaw + Galizia and Bukovina from Austria. Alexander's fixation about being saviour of Poles materializes. He creates Kingdom of Poland from Duchy of Warsaw and Austrian Galizia (roughly twice as big as OTL one) but instead crowning himself (OTL he also never bothered to be crowned King of Poland, unlike his brother Nicholas, crowned in Warsaw in 1829) he installed his second son (Alexander Jr, born in 1798) in Warsaw. To seal peace with defeated Habsburgs Alexander Jr marries Habsburg princess, and, although he remains Orthodox himself, their children are raised in mother's faith. Bigger size of that Polish Kingdom compared to OTL one means not only, that Poles are less bitter, but also that there are more jobs in administration and army, and that would reduce number of jobless frustrates like Wysocki and his colleagues).