Even had the French shaken off their lethargy, I doubt that they would have made it very far, if only for logistic reasons. The relatively urbanized nature of W Germany would have acted as a breaker for any advance, even in the face of only a light defense. IMO, they would have made it maybe half-way to Munich, and maybe have gotten to the gates of Köln, maybe. However, this is much better than what happened historically! I think the French would have learned some key key key early land-warfare lessons, and then beneficially use them later on. Maybe France would not have fallen. And who knows what political repercussions would have happened because of some early allied successes? Poland might have hung on another 2-4 weeks, and maybe the Soviets might have felt not so compelled to their treaty obligations. French morale would have been quite high after even a successfully mini-campaign. However, would the French army have held their positions in W Germany or retreated to the safety of the Maginot? My guess is the latter, so any territorial gains would have been temporary.