References are : Oleg Sokolov "Le combat des deux Empires" (very surprisingly, I don't find an english translation ?) and Lieven "Russia against Napoleon".
I still think that losing 500.000 experienced soldiers all horses and 1.300 guns was simply irrecoverable by the time. 1813 was numerous, but never had strategical initiative and melted down at high speed due to lack of training and seasoning. Only the cadres were still efficient, if war-tired.