Let's assume that at the Congress of Vienna, the great powers are more land-greedy and wish to ensure less political fragmentation in Western Europe than OTL (as better protection against France). They ditch the idea of restoring as much of the pre-Napoleonic status quo as possible, and just go for rough balance of power between themselves (princes that get dethroned as a result are deemed to have been too cooperative with Napoleon, or did not pull their weight in ther fight against him, and so are unworthy of restoration). France also gets an harsher peace than OTL, and has little say in the peace treaty.
Russia gets Finland, Congress Poland, Posen, Krakow, Galicia, and Bukovina.
Prussia gets Swedish Pomerania, Rhineland-Westphalia, Danzig, Saxony, Hanover, and Limburg.
Austria gets Tirol, Salzburg, Old Bavaria, Illyrian Provinces, Lombardy, Venetia, Modena, Papal Legations, Lucca, Tuscany, and Naples.
Sardinia-Piedmont gets Genoa, Corsica, and Parma.
Southern Netherlands, Lorraine, and Alsace form the Kingdom of Lorraine under the Wittelsbachs.
Franconia is established as a new German state under the Wettins.
Baden gets Rhenish Palatinate.
Britain gets a personal union with the Kingdom of Netherlands.
Sicily stays a separate state under the Bourbons.
Note: in the map, I used a grey line, same as the German Confederation border, to mark the Kingdom of Poland within Russia, not a dotted line as the other subkingdoms (Norway and Finland), for simplicity.