Cool setup and good question - we have 3 panels for ~240 watts and they never have trouble keeping the batteries charged, but we live in the southwest and usually don't camp under more than 50% canopy cover.
For us the reason I'm considering switching to other panels is that the weight of our classic panels makes the shell
much harder to lift. If I lived closer to a dealer I would consider having them put on stronger lift bars, but I think it will be easier to just lose the pounds by switching to lighter weight panels for the same total watteage.
We looked briefly at adding more to try to convert either of the remaining 2 items to solar (air conditioning or heating), but we couldn't accommodate the extra solar needed or justify all the extra electronics, super-size batteries, inverters, and other purchases to make it work.
We are seriously looking at converting our stick house to full solar (including heating) and that will be challenge enough for us.
