Adapting seems natural to me. If Wing Chun was truly designed for close quarter space, say like a linear alley way, a room, or some other some other space restricted area like a crowded street then I can see where the narrow stance and footwork would come in handy, but when there is space then the footwork needs to be able to adapt. This is true for all fighting systems.
Below is a picture from the 1900 China. If a fight were to kick off in this environment, then you would want to beat your opponent as quickly as possible while taking advantage of limited space, before people started to get out of the way. If you were walking down an alley in this environment, then you would have the same challenges of limited space. Both scenario make getting the fight over as fast as possible would require forward aggressiveness which is common in Wing Chun practice. I can't visualize a scenario where Wing Chun waits to be attacked. The narrow stance almost demands you go after the opponent fully dedicated. The Chi Sao and Bong Sao and trapping movements seems like something that would work when you are jamming punches with forward movement.
If my assumptions are correct then Wing Chun would have no other choice but to adapt when there is open space. With open spaces people are now able to cut angles and literally be on your flank. Now take downs would be able to take advantage of footwork designed for limited space. If someone wanted to fight in a less congested area then their footwork and defense would have to naturally adjust. I know that some Wing Chun schools fail to adapt in this way, but I don't think that's a System issue. I think that's a Purity Issue and not a fight logic issue. Fight logic would dictate that we adapt techniques according to the environment we are in.