Otto
Since your trailer is newer you should be fine adding a battery like the one in your trailer. That should extend time between charges.
A generator will keep you charged up day to day, inverter generator cost more but are quieter and use less gas. At least 2000w unless you want AC, that takes 3000w.
You can get LEDs for $2 or so off of ebay. They really do use less power. A few in the fixtures you use the most will do.
We have the above and it all worked nice but nothing gave us the freedom from worrying about the battery like the simple 230w solar system I cobbled together. Unless it's cloudy for days we can't use the power it puts out. We light the rig up from end to end, set the stat at 74 all day and night and can watch TV/DVD, listen to radio and run the fans all we want. The battery is always fully charged at night and losses little overnight. We never run the generator for charging, but we do take it as a back up. It would cost around $400 to make a system like it.