There's generally 2 things to do for commuting to work like that:

1. Keep as much stuff at work as possible. Whether you can do this depends on your job, but I have a cube, so I keep an entire change of clothes in a drawer - shoes, pants, shirt. If drive 1 day/week, you can change clothes then, though to be honest I work in a climate controlled office building - they just don't need to be changed very often.

2. Get a rack for your bike. If you have to carry everything, panniers work, but if you don't or your stuff isn't that big a rear trunk bag -


Panniers are totally manageable, and required if you want to carry a lot of stuff or a laptop, but a trunk bag is nicer in my opinion. No noticeably wind resistance (I can feel it with panniers), doesn't make the bike slightly heavier on one side. Either one it totally workable, I just like the trunk bag better. :-)