I think Hitler will try the unification of Austria and Germany first. Germany needs to ransack for supplies. Austria still had a large enough economy for this to take place. He needs the supplies to attack Poland. Of course he'll likely invade Czechoslovakia first...Danzig Corridor. Much the same situation as the Sudetenland and the Pole would definitely fight to keep it. With someone like Hitler whatever you let him have is not enough, he's just going to keep coming back for more.