I agree with pianotuna -more solar.
I am not intending to insult your camping style, as we are all different. But... ;) , with 2 "deep cycle" batteries and 200 watts of solar, I don't see why you are running low on power, except in the winter. If you have all LED lighting, and are not watching TV all the time, seems like you would be good for days.
I say this, as we have had two trailers with two Group 24 batteries, and 200w of rooftop solar, and could go as long as we wanted. The batteries were topped-off each afternoon, and I could run the furnace in the evening and morning (didn't need it overnight while camping with DW). In the winter when I went pheasant hunting, I was still able to run the furnace when I wanted, as the solar and batteries kept up each day. I have not owned a generator.
You may want to look at your electric usage. Your style may require more power, but I think you would be ahead to add another 100w panel to top-off your batteries each day. If you add another battery, yet you are not fully-charging what you have, you won't gain useable amp-hours; you will just be storing the same amount in 3 batteries, instead of two.
Just my thoughts.
