Hey. I've done 2 long cross country trips. Both starting in Omaha NE south to TX, through AZ, CA, and back.
All on my 1982 CB650. And am doing it again, sometime this winter. Jan-March trip along southern coast to Key West FL.
BOXNIFE has some real good suggestions. Can't find anything I'd add to his summary.
The best thing is to find a routine, when packing, unpacking each day.
srust58: has a great idea to change the route. Badlands state park through the Dakotas will be far far far far better than what you've planned. + great camping options all along that state as well.
I'm subscribing....
if it works out, I'll tag along on your way through the midwest back to Buffalo. I've got family in Rochester, NY, and would be a great excuse for a visit. (I'm in Omaha, NE, but can meet up wherever you decide on your final route back home.)