At the least we could have moved into the Central European countries occupied by the Soviet Union.
I don’t think invading the Soviet Union itself would have been wise.
Those Central European countries were promised by the Allies to the Soviet Union as part of the deal to keep the Soviets in the war.
Sure hasn’t worked out for several badass armies who tried
Wehrmacht
Le Grandé Armee
Both immediately come to mind
Even if you take the big cities