We have a 32 ft Fleetwood Encounter with 6 of us. With kids, everything gets more use, lights are left on, water is used more, more than one tv is on at a time (running off one 300 watt inverter), electronic devices that have to be charged, etc.
We have 400 watts of solar and only 2-6 volt batteries. We've gone 5 days with no generator usage in summer time at the beach and only running out of fresh water and waste water space.
We live near Silicon Valley where there is no shortage of cheap supplies of solar panels, I think you can find similar deals down in your area, too. I pieced together and installed the system myself for under $500. The Tracer MPPT 30A controller I'm using is not perfect, but it gets the job done, it's reported up to 24 amps into the at and has them topped off by early afternoon in most instances.
I would say that if you don't have any really large draws on your batteries, such as a big inverter, you should be fine with just your 2-6 volt batteries. Especially considering you're already getting 2 to 3 days out them as it is.