Depending on were you stay. Motels provide soap shampo even razors most of the time.
There are all kind of folding brushes and tooth brushes out there.
you really do not need a bike cover along but if you have bag srtapped on you need covers for those. Into all lives some rain will come.
Glove liners work well on cool days and nights ,then slipped into heavyer gloves if it gets cold. If you lucky both of your cell phone use the same charger take 1.
I use the bike to charge phones.
Try laying out what you each can not live with out. Then give up a few things

.
And try agin.
My wife and I can pack all we need for 4 day trip in the tour pack , hard bags and a tour master we remove the round bag top and strap on the tour pack.
Also two weeks ago met a couple at the S&S party in Lacrosse WI.
They lost a bag off the back when straps came off. In it was wallets cash and all ID.
keep cash, and ID's in different places.
Anything can be lost Or stolen no madder how secure. I sucks to lose your cash it sucks to lose your ID but to lose both at once on the road it is really going to be a bad day.
Enjoy the trip