Sorry about that, I had a brain fart combined with a poorly worded paragraph. By 'talking about 1943,' it should have been 'talking about the situation circa early 1943 in which the hypothetical D-Day landings occur while the Soviets were historically slugging it with the Germans on a temporarily stabilized front,' that is, before they got the ball rolling again after the failure of Zitadelle.
Regarding German redeployments, had the WAllies tried invading a year earlier I'm not entirely convinced the German response would have (or could have been) much greater than it was. Sending over several corps' worth over the course of weeks or months is one thing, but most German forces in the East were heavily engaged as it was and extricating large quantities of them simultaneously would compromise the front.
Even operating under the assumption that Hitler would abandon the Ostfront (an uncharacteristic decision knowing Hitler) in the event of a meltdown in France and send west, say, 50 divisions, if OKW wanted to have any chance at all of forming a coherent defense they would pretty much have to acknowledge surrendering everything west of the Rhine. Not sure if Hitler would go that far, more likely he would order another Falaise-style counterattack and get himself outmaneuvered again throwing men piecemeal into the grinder where they would be hopelessly outclassed by Allied mobility and firepower. Even allowing a German strength of over 100 divisions on the Rhine it would have been much more of a problem than it was in OTL, but even then once those fixed defenses are breached there would be literally nothing between the Allies and Berlin but a lot of flat, dry "tank country."