Leave your work footwear at work, assuming you have a spot where they won't walk-off.
![glasses2](http://www.bikepacking.net/forum/Smileys/Lots_O_Smileys/glasses2.gif)
My old commute was about 10% of your new commute, but I once I got a set of footwear to simply leave under my desk packing became easier. I also stashed some spare clothes in case I was a bonehead and forgot a clean shirt, underwear, etc.