I would argue that by the Battle of Moscow, Germany already had no chance of winning the war. Germany completely underestimated the Soviet Union's will to fight before the invasion, and when Operation Barbarossa failed as a kick in the door that would collapse the entire house, the Germany army didn't have the momentum needed to crush the Red Army before they could regroup at the last line of defense. A good indicator is that the British, who were afraid that any resources or materiel sent to the USSR would be captured and used against them, began selling tanks and supplies. When Operation Typhoon failed and the Germans were beaten away from Moscow, the entire world saw that they weren't unstoppable as previously believed.

As far as a legitimate chance of winning, I would have to say it was never a possibility. The invasion plans were incredibly optimistic and glossed over a lot of important details which came back to bite the Germans in the ass later.