What if Nappy decides to split the Grande Armee into 3? 200,000 troops would be sent along to St. Petersburg, the historical route and Ukraine. It would solve many of the supply issues and assuming supply problems are alleviated he might still have a historical count of troops at Borodino. The idea of this plan being that even if one of the columns is defeated, Russia will still be losing valuable land.
After all this does follow its old motto: march divided, fight united.