In my personal opinion the smallest solar install a person should consider given todays market is in the 200-300 watt range, if you are expecting it to significantly support camping operation, a single 100 watt panel works great for maintaining batteries in storage, as well as providing power to cover the smaller parasitic loads (LPG and CO sensors, etc.) what it likely will not cover is active camping. Take for example a typical modern RV absorption refrigerator, a typical full size Norcold or Dometic refrigerator DC control system will draw between 6-12 watts continuously during operation (most recent Dometic units have a 5 watt defrost heater that runs continuously that can't be turned off). This adds up to about 288 watt hours per day just to run the DC controls while running the refrigerator on propane, you can expect about the equivalent of 5 peak output hours per day on a flat mounted solar panel in the common summer camping season (maybe 6-7 in very sunny parts of the country), so assume about 500 watts per day on sunny days from a 100 watt panel, sunny days are a lot less common than most people think even in relatively sunny parts of the country, so having said that, you would be lucky if the 100 watt panel makes up for the drain caused by your DC control circuits alone. So sure it is better than nothing, and will slow the rate of discharge, don't expect it to make up for any use losses.
p.s. one place these smaller 100-200 watt solar installs do help is when using them to top off the batteries after running the generator in the morning hours. Lead acid batteries charge fairly quickly up to the 80% capacity point, then slower and slower as they approach 100% full, using a generator for the bulk charging then solar to top them off the last 20% makes a degree of sense.
