Keep a battery operated (or cigarette lighter adapted) mini shop-vac in your vehicle, along with a tarp, 2 straps, and 2 towels. When you get off the river, put the boat clean on your tarp, wipe it dry and clean with the towels, shop vac it flat, roll it tight and neat, use the strap to secure it, and wrap and strap it in the tarp to keep it clean and safe.
Rolling boats is fine, even for long-term storage. A good, seamless roll inside of a tarp makes your boat really easy to store and transport. I recently unrolled a bucket boat that has been rolled and stored in a shed for a decade or more and I saw absolutely no damage from this. It was a hypalon Avon, so I can't testify to this kind of longevity with PVC boats, but I keep my Aire duckies rolled tight and have yet to notice any adverse effects.
Regular use of 303 and regular cleaning is a good way to make your inflatable last the 30+ years that it should. Unless.... it's not a Saturn is it?