I leave a pair of jeans, underthings and a couple of shirts in my desk, towel and shower stuff in my locker at work. Typically what I bring with me is a palm sized emergency kit (tube, multitool, tire levers), a container with lunch, my work ID and wallet. I could carry it all awkwardly in one hand.

I do have a garment bag that I use if I feel like dressing up at work, but that pretty much doesn't happen in the winter.