Not much to offer for advice -- my only experience is a 2-day MS tour I did where I camped. I think I just brought my hanging toiletry bag and a plastic grocery bag (reduce, reuse, recycle! ) for the dirty laundry. And I think I showered (and pretty much lived off-bike) in my Tevas.
But I did want to wish you good luck and I hope you have a great trip...full of sun and puffy clouds for shade. Not too hot...not too cold, and little wind, always at your back!
2007 Seven ID8 - Bontrager InForm
2003 Klein Palomino - Terry Firefly (?)
2010 Seven Cafe Racer - Bontrager InForm
2008 Cervelo P2C - Adamo Prologue Saddle