What a letdown! I was expecting this kind of final scenario if he Ardennes offensive was unsuccesful but even i manage to achieve what historically Germans couldn´t in the end it doesn´t change nothing.

Sometimes PC sticks too close to history and doesn´t allow for needed "what if?" scenarios. This also happened in the next scenario after Stalingrad where you are told that the city had just fallen after you brilliantly captured it just minutes before.
What´s the point in getting victories if you are going to lose in the end unless you get brilliant victories one after the other? There must be an intermediate point between fantasy scenarios (USA invasion) and the historically correct fall of Germany.