The Soviets lose lendlease, but they are not caught by surprise and retain areas with extensive manpower, resources, and industry quickly overrun in our TL. Russian military production is considerably higher, and they can hold onto more food-producing areas. I'd say it about balances out, and the war grinds on untill either the Soviets or Germany runs out of warm bodies, somewhere in '45 or '46. No compromise peace: neither side is willing to allow the other to survive as a strong threat while they are winning. I'd give roughly 60-40 odds in the Soviet's favor, depending on how well or badly they do in the first year of fighting: if the Soviets manage not to lose too much territory in the first 12 months, they can probably win it, although at human costs possibly exceeding our TL. (Note the lendlease pipe to the Soviets didn't really start to flow in quantity until late '42, by which they had stopped the Germans cold in spite of being seriously caught with their pants down).
The Japanese might intervene on the German side, but if the Germans seem to be winning, why suffer terrible losses against an enemy with crushing superiority in tanks, etc. to gain some frozen wasteland? And if the Germans seem to be losing, why suffer terrible losses against an enemy with crushing superiority in tanks, etc. and possibly get driven off the mainland altogether? (Even in '41, before the undoubtedly grotesque buildup that would occur during the war, only a small percentage of the Soviet army is needed to effectively stop any japanese advance into eastern Siberia cold. Repeat after me: The Japanese have _nothing_ resembling heavy armor. Japanese tanks are dinky little things with thin armor designed to chase lightly armed Chinese resistence through rice paddies).