Let's say that rather than marching >500,000 men straight to Moscow, Napoleon split his force into 3 columns, marching separately under different commanders: One to St. Petersburg, one to Moscow, and one to Kiev or somewhere else in to the south. This would have made supplies easier, and if each column is of roughly equal size - 170,000 or more, at least - then the Russians still can only just barely raise an army that could rival any of these columns' sizes, so it's not as if the French would be opening themselves up to be defeated in detail. Even better, it might goad the Russians into attacking instead of going for a scorched earth and retreat strategy.