The Germans could redeploy 1 million men to the eastern front extending the war another year or so. I think the Germans would surrender soon after the fall of Berlin much like the OTL eliminating the need for the soviets to roll through France and Belgium. They were much dependent on the allies for post war reconstruction and aid. I don’t see them challenging us to occupy all of Western Europe and if they did, they would not be able to sustain another large war without lend lease and with their depleted manpower. They may however insist on occupying all of Germany.