Exactly. At the end of the day the nazis were going as fast as they could. The speed they could go was determined not by themselves but by the practicality of the enemy forcing them to fight for every inch.

How are you going to go any faster? Ultimately the only way to do so is to have not launched the offensive when it was. If you're launching the offensive at the time the nazis did and under those conditions and resources you are simply not winning it. It was too late.