I think solar thinking goes along the same lines as how you view your trailer. Those that think of as another home only on wheels seem to need more and more and more power. The must haves for them are things like Microwave Ovens, A/C, Television, etc., etc. For those folks a large battery bank and lots of solar panel
are needed to make them feel at home.
Then there's Jack, myself, and others that look at our trailers more as a convenient place to sleep along with cooking and eating in bad weather. Our lives are spent outside as much as possible. Rather than TV there's a walk or two around the campground. A visit a neighbor. Sometimes a fire to sit around and talk, etc., etc. For us the power needs are quite small. We do more to reduce our power needs with such things as LED lighting
, no water pump, no TV, etc., etc. Therefore a smaller solar system will work just fine for us.
In my case I have a 74 amp hour battery on the trailer, and 60 amp to use with my ham radio should I throw up an antenna. My 65 Watt solar panel keep both batteries charged.
We spent almost a 100 day each of the last two winters traveling the southwest (200 days plus). No hookups for most that time, longest stay was 3 weeks in Death Valley with no hookups.
My point is look carefully at what you want to do.
If you're going RVing (staying in RV parks) you don't need solar since you're always connected to electricity.
If you're week-end camping rather than one to two weeks in one place. You might want to consider what's using power that you do without for a week-end. You still don't need solar.
If you're on the move a lot, only spending 2 to 3 days in one place, you might not need solar. (Depending on the weather, I can go from 4 days to two weeks on a single charge. The only exception was when the temperature were in single digits and the teens.)
If you're going to be in one place for more that 3 days often, then solar makes sense.
Look carefully at your need and wants before spending a lot of money you don't need to spend.