Well, the Treaty of Paris would have remained as it was originally, with France loosing less territories.
I could see Bonapartism being less of a mythos and legendarium with an emperor not ending it all in all his glory, but in the same time remaining a fairly noticable political force ITTL, without the "purge" of 1815.
If Napoleon pulls himself together and waits just some years, his return will me more easy, since a united European front against him is, by then, quite difficult.