Fair enough. I've done it three different ways:
1) bag drops with clean clothes at 350km-ish intervals on LEL that didn't necessarily coincide with my sleep stops
2) carrying everything in a monster saddlebag for a 1300km DIY
3) not changing shorts at all on PBP
Of course, but in terms of time I would rather shower and change where I sleep, my planned stops at other controls are minimal.