One must not forget that there´s always the danger that the Red Army would let the panzers of the relief force in but not out. Then what would Manstein fight the Red Army with? Or stop the pincers clutching around the relief force if the Red Army attacked them?
Besides with 75,000 men and 500 tanks the German force was not really a force that would crush through the Soviet lines and hold it, I think.

Operation Winterstorm

The SS panzer troops from France would not be available until Feb 1943.

__________________