I don't know if this is a splurge or a steal, more of a tip:
Right before a trip, I get a professional blow-out. I then use the dry shampoo whenever the roots are looking dirty. A few days into the trip, I make an appointment for a professional blow-out, via the hotel concierge (I do the same thing with manicures). I do this wherever I go, and find it a lot less stressful than trying to do my own hair on the road. FTR, I have completely unmanageable, frizzy hair that never looks quite right if I do it myself, but takes beautifully to a professional blow-out (and a professional blow-out lasts 4-5 days on me, looking perfect).