It must be said that there were some in Poland who still dreamed of a Greater Poland. In view of the Russo-Polish War which ended in 1920 with a Miracle victory by the gallant Polish Army I would think that that dream was unrealistic. Having said that the Polish government always considered the Soviets to be a serious threat to them. However, the rise of Hitler and his constant tirade on Danzig showed that the Nazi regime was one that no deal could be made with. A Polish-German alliance would have put a very large army on the Eastern Front against a Red Army that suffered from massive problems. Remember even in 1939 the Red Army suffered greatly during its war with Finland and even the Poles who were fighting the Germans still managed to inflict loses on the Red Army. No I do not think that it is likely in anyway to happen. A different regime in Berlin combined with a different treatment of the Russian people might very well have won the war in the east.