One of the reasons why the Soviets gave up in 1920 was that they were at the extreme limit of their ability to wage sustained war. It was too soon after the Revolution and long before the 5-year plans gave Russia the economic base to wage WWII-style conflicts.
So there probably still have been a Poland, albiet the eastern boder would be more west. This might have created an environment where Weimar Republic is given more latitute for defence, and probably butterflied away the rise of National Socialists (Although some other right-wingers may have stepped in. It is difficult to imagine a more repugnant regime than the Nazis).
Conceivably, as already postulated, WWII becomes East vs West, Rightism against Leftism, as France/Germany/UK opposes USSR, with hostilities breaking out around 1944 if Stalin or a proto-Stalin succeeds Lenin.
Since Trotksy heavily favored peace with Poland rather than war, a more positive Soviet outcome may have discredited him sooner. This creates interesting Buttlerflies, as Lenin may have done more to prevent a Stalin type from dominating if he was not feuding with Trotsky.