We all know what happened that fateful day in September 1812 when General Barclay so ably filled the dying Kutuzov's shoes and turned the tide of the battle magnificently. And of course, that was the limit of Napooleon's expansion. The French Empire ceased expanding and, over the next hundred years, its possessions in Germany and further Eastward were whittled away although Napoleon's legacy is a strong and stable France, might things have been different had he won at Borodino?
Yes and no is my answer to that. If he had won the battle and annihilated Russian forces, then yes, I imagine he might have conquered Russia itself and formed a nucleus for a world-spanning French Empire.
But suppose the Russians were able to retreat in good order and regroup? In that situation, I imagine continuing harrying by Russian forces along with a scorced earth policy might mean that tired, hungry and miserable soldiers of France found themeslves facing enthusiastic and implacable defenders as Moscow or St Petersburg resisted the invasion, and no doubt pursued Napoleon's ragged band of adventurers into oblivion.