We all know how it works in real life, kidding aside. You can have 2000w of solar with a sky like in the photo and it won't help. Once the sun comes out, you have to recover the battery bank while still running the RV. Now having more solar will help.
If you only have enough solar to get by on the mostly good days, you now can get back to doing that, but the batts are still down and sulfating so you need more than enough to get by. How can you get them back up if your roof is too small? Easy, carry a gen to do the recovery.
I did ask the OP what his plan was and said it "depends". It is all scenario. You can go camping off grid under the trees in mostly cloudy short days in January here, and solar will do nothing at all for you. It is all about how big is your battery bank for how long you are staying and recharging with the gen/charger during gen hours in the park.
In the Class C we have now, I can drive out in the open during the day and get some solar plus alternator charging to help a little. Still trivial in AH compared with usage. In the nicer half of the year the solar is much better if you can get in the open and use it.
Scenario is everything! The OP needs to answer the initial question, "What is a good system" for his scenario?" by stating the scenario. Then we can easily suggest what he can do.
