I looked ast all kinds of options when we got our Weber Q. In the end, I decided a portable tank was the best way to go. I got a 10-lb "squatty" portable tank that has the same base ring as the regular 20-pounder. I bought a "base stabilizer ring" from CW and bolted it down inside a stow-bin. The tank snaps in snugly enough that no additional restraint is needed for travelling.
With that set-up, where I put the grill when I want to cook on it is not restricted by the length of a hose from the RV's tank.
