I'm pretty positive that as long as the war stays conventional, the West will keep the air superiority, anyway what time or day the East attacks.
That means, most of the Russian tanks and airplanes will be blasted to pieces, and only the lightly armored vehicles and the foot soldiers will be a serious problem.
Furthermore, in the 80s, the Leopard II was probably the best tank in the world - even today it's among the best. Afaik, unlike the French, the Germans didn't have battlefield management at the time, but that can partly be done with maps, erasable pens and conventional communications.
That will dramatically reduce problems with Soviet soldiers and light vehicles.
A very serious question is, whether the Fulda Gap weakness is discovered by the West before or after that war. If the West is unprepared, Western Germany is split in two, and most of Western Germany's industrial and raw material base is destroyed in the first one or two days of the battle. But even that will leave most of the western German army intact, and supplies will be brought in by the allies.
By that time, the French will probably show the Soviets what battlefield management means, and they will help drive the Soviets out, despite tanks of similar quality on both sides.
All in all, I do expect much of Germany to be run over by a Soviet surprise attack - but also a pretty early rebound, that will then lead to a conventional liberation of Eastern Europe.
Only question is, whether the nerves of the top brass on both sides will be strong enough to keep a nuclear exchange from happening. I suppose as long as the West doesn't liberate more than Eastern Europe and other satellites (and not the Soviet heart land), it might end just like the Cold War, but with several million more deaths.