Oi vey!
I used to live out of a small 20" rollaboard for three weeks at a time. My secret? The hotel laundry! Especially when on business. I would bring sets of three - three undergarment sets, three slacks, three shirts. Wear one, pack two. Laundry every day and you can skip a day in emrgencies or if they don't do same day laundry.
If I'm feeling cheap and I'm travelling on my own dollar, I'll take some Tilley travel underwear and socks. I can wash them in the sink and they're dry by morning.
If you're going to BsAs, though, eschew the hotel laundry and just drop your clothes off at one of the nearby laundries. Hotels there charge so much for laundry that it can often be cheaper to buy new clothes. The local laundries are far more reasonable and do a great job. Just remember - "plancha la chemisas."
