Yep, the Germans were out of good options by mid-1943. Even if a dedicated team of Neo-Nazi's were sent back to 1943 from 2010 AND Hitler listened to them, it is hard to see a good outcome for the Nazi's. It is too late for a serious atomic program, even if the Nazi have blueprints for bombs and nuclear reactors. It is probably too late to bring in jet fighters in quantity before March 1944, when the USA broke the back of the Luftwaffe. If Germany fortifies Normandy heavily, the Allies are likely to just adjust the invasion plans to elsewhere. If the Germans adopt the "optimal" tactics on the Eastern front, they merely delay the Russian advance. And even if i am wrong, and Nazi do stalemate the Eastern Front and successfully drive the UK/USA attack into the sea, by 1946, the USA is using nuclear weapons on the Germans on a regular basis.