I was thinking something similar this morning, but not with that kind of mileage. Between the packing, unpacking, changing clothes etc... the pedaling is the easiest part of my commute. When it was just over 2 miles it seemed like I was just getting warmed up when I arrived, and would take me longer with the prep. My latest ride is around 7 miles and the extra pedaling time makes it feel more like an actual trip now even when I loaf to keep from sweating too much. But even a one way commute like that would be a huge change for me, kudos to you for being able to do that.