I use a 20" rollaboard, plus, if necessary, a small day pack (and I do mean small--I am 5'2" and bought my day pack in the children's department at REI!). For a week's trip I would not need to do laundry. Two pairs of shoes at most, and the rest of my clothes easily roll up and fit in the small suitcase. Of course, since I am 5'2", my clothes are small also, so YMMV.