Assuming you have laundry facilities available. I always like to launder before packing for a return trip, just because it's one less thing to do upon return; keeps the suitcases fresh; and allows for tighter packing. I, then, get to live out of my suitcase for awhile once home, as an adfed bonus. If possible, I book at a hotel with washer/dryer. In Montreal, I was attending a convention at a hotel without cleaning equipment. I found a public laundromat a mile away. Lugged my clothes down there early evening. It closed late afternoon. Twas a good thing I had an extra suitcase with some space and enough clothes to last beyond even my normal wash cycle at home or I might have been a naked Amtrak rider. Thankfully, I did manage to wash and dry in Toronto a week earlier on the trip. I always overpack, therefore, ideally to last the entire trip and then some, just in case. For anything over a few days, that means extra luggage, especially for a two week trip.