Just wanted to add, by adding a battery monitor (Trimetric 2030) within a few trips you'll be able to tell for sure how much usage you have. There is an old saying to figure out how many watts of panels you need and double it. Using a good monitor will allow you to zero in on how much you will need. Windy Nation is a good site for off the grid equipment. With power, cheap is not always a good thing, unless you are getting top of the line equipment at a reasonable price.
test have shown you can add 20 to 25% efficiency by pointing your panels. Maximizing your efficiency and monitoring your power collection at least for the 1st 6 months will give you lots of information and peace of mind....
2015 Wildwood 181 BHXL. 2005 1500 Ram Hemi 4x4 W/package