Still, I believe that the Russians would still have won in the end.
You cannot control a land mass as large as Russia. That’s why the Mongols never tried to rule Russia directly-they regularly exacted tributes, but otherwise left the Russian principalities alone (Russia was not yet united as a polity then).
Best case scenario. Hitler takes Moscow, which leads to a coup, with Khrushchev replacing Stalin.
I believe Khrushchev would have taken a much different course, basically abandoning Bolshevism, at least for the duration of the war, to unite the people, and ultimately defeating the Nazis. But certainly, the Soviet Union would have been a much different place after the war.