Not true. Dont have Stalin as Soviet Leader, dont industrialize east of the Urals in the 1930's, have the Nazi's capture all Soviet Industrial centers in the West and there's not much the Soviets could do to oppose the German conquest. The Western Allies alone could not supply the Soviets with all the equipment they would need to fight the colossal battles that occured on the eastern front and if the Soviet insutrial centers are in Nazi hands with little-to-no industry further east the Soviets will simply lack the means to fight on even if they had the will and would have to capitulate.
I think the "at that point" pretty much covered the scenario under discussion.
If one puts in sufficient POD that the entire world is different, then anything is possible, that, however, isn't how this sort of scenario is reasonably discussed. Given the OP question it is clear that OTL's war is the one under discussion, meaning the POD would have to occur post 1942 if not later.