I don’t see it. More likely scenario is the Wehrmacht high command eats their Christmas goose in the Kremlin. That is around the time Japan jumps on the Pacific end of the Soviet Union to take part in the spoils. Then Germany can return their full attention to finishing off Great Britain. That means we had better step up our production of war materials for the British so they can withstand the likely invasion next spring. Otherwise it will be America alone against the combined might of a triumphant Third Reich and their Asian ally.
I think when Russia does fall, Churchill will get voted out and once that happens I don’t see Britain staying in the war. I’d bet they’d sue for peace since becoming a vassal state like the Vichy would be better than to have the island occupied by the Wehrmacht.