I doubt that the British and French would not have shipped massive amounts of equipment to Russia as aid. Both would have been more than willing to give the Soviets lots of weapons and supplies to fight the Germans.
Also, the Germans would still have had to leave a fairly large force in Germany to defend against the possibility of France and Britain entering the war at some point. One cannot rule out the US doing the same.
If at some point the Western Allies do enter the war it is actually worse for Germany the longer the delay to that point is.