My commute is 8 mi and fortunately I have access to a shower. With the way I ride and the amount of sweat I generate, I need it!
I carry clothes in my pannier. I've found that strategically folding them works better than rolling them in terms of wrinkles. I do leave clothes in my locker at work for reuse on other days.
I don't wear makeup ever and my hair is very short. If needed, I could just rinse my head under a faucet and my hair would be fine.