IMHO, the ideal RV electrical energy approach for MAXIMUM drycamping flexibility ... and installed in this order ... is:
1) A main RV engine that can idle quietly and vibration-fee for hours fed via a large fuel tank.
2) A main RV built-in generator that can run quietly and vibration-free for hours fed via the main engine fuel tank.
3) A small portable generator that can run quietly for hours from it's tank and that you bring spare fuel along for.
4) A portable solar system for picking up the sun whether the RV is in the shade or in the sun.
5) A solar system with some solar panels mounted on the roof - without having to put holes in the roof to mount it.
If your rig has 1) and 2), or at least 1) and 3), then go for number 4) ... and maybe 5) later, after 4).
:C