Why was Napoleons delay of the retreat feom Moscow such a grate blunder?

Because he had decided to stay longer during the winter months, the weather was extremely harsh and he and his army were not prepared ... Napoleon decided to invade Russia because Russia refused to stop selling grain to Great Britain.

It was a great blunder because the enemy (I forgot who) caught up to the tired army and killed more than half of them (I also forgot the name of the army)