The above commentators bring up good points, but one additional point to remember that this would be a huge battle. It would be the largest, in terms of troops and firepower engaged, in history to that point and possibly for centuries.
Both sides would know that this would be for all the marbles. Most of the German air force and nearly all the Soviet air force would be committed, it would take logistics priority, plus any army reserves it might have. If the Germans do this right, and their planning was always pretty good, they would be pulling the Luftwaffe from the Atlantic and Med and at least shutting Rommel down (denying him logistical support) to concentrate on taking Moscow, probably also nothing happening around Sevastopol and Stalingrad. The Soviets we know were planning to concentrate on defense.
That means 1943 would be quiet. Even the winner of such a battle would have little left to do anything else other than recuperate. If the USSR loses, they lose their major rail, industrial, and administrative center, their air force is pretty much gone, and they have lost their reserves. I think they capitulate in this scenario. If Germany loses, we actually get something close to the situation the British and American planners anticipated they might have to go back to France early, to get on the ground on the continent before the Axis collapse. No Battle of the Atlantic (because the Luftwaffe can't participate), not much to put into the Med, and on the Eastern Front they are trying to improvise a defense with whatever remains, like they did several times IOTL, though the Red Army would probably be too chewed up to throw them out of Russia entirely. Also, IOTL there was an assassination attempt on Hitler in 1943, in the case of a German defeat at Moscow such attempts would likely get more support and be done more urgently.
Btw, from the Axis perspective, I think it was in their interest to make the attempt. In 1942 they were in a "win now or go home" strategic situation.