Has anyone done this? Placed a flat water tank on the storage platform in the crew cab when you may need to have extra water. Use a small pump to transfer to the TC tank when needed. If it was flat...
That seems like a lot of money for a tank. Might be fine if it were installed somewhere in the camper. My tank is 35 gallons and I have never run out where I needed more water reserve. When I had a trailer I did carry a 7 gal tank of water and used a small pump I purchased at HF to pump the water into the holding tank. Way less money than you are talking about.