Here is a pic of my WRR in CO on the TAT. I used a medium Wolfman duffle, mainly because my tent poles would fit inside. Otherwise the small would have been fine I think. The medium never did get filled completely. Notice the front fender and tube bag. The fender is just not stiff enough to hold the weight IMO. The two of us with WRR's added some light tent cord suspenders to help support the weight and keep the fender from flopping up and down too much. My partner delayed this tactic and wound up with a crack in his fender that we sewed up with multiple small holes and wire lacing. Fair warning! I always kept my sandles strapped to the back, along with any unworn jacket, protection, etc. The jacket I wrapped up in a bath towel to keep it clean, and the towel was a good piece to add under my pillow when camping. This setup provided plenty of space for everything for the entire round trip.
Lefty, I guarantee you have too much stuff on your bike! All three of us on our trip made a stop early on and sent big, heavy boxes of unused gear back home. You really, really, want to cut back and make the bike as light as possible. I don't know what all you have loaded, but all of us were very comfortable from the heat of NV to the cold of CO passes, had camping gear and required tools. In retrospect there are a few things I could have omitted even yet, but not a lot.