There were two issues for me: money and running cable from the roof. I dealt with the money issue by doing it over a period of time. I started the first season with a single 12V to dual 6V battery conversion. Prior to the next spring I ordered two panels and a PWM 30A controller that was big enough to support 4 panels.
The cabling problem was solved by someone detailing running the cable down the gray tank vent. My fridge vent was at the opposite end from the battery compartment, so that wasn't good for me. So now I have two panels on the roof feeding my 220AH battery bank. I haven't decided on an inverter yet as I use a Coleman camp coffee pot and propane stove for cooking off grid. I have a 300w 12v receptacle inverter I could run a TV with but haven't yet as I would prefer a hard wired solution.
2015 F350 XLT PSD CCSB SRW, Andersen Ultimate hitch
'12 Cougar High Country 299RKS, Mor/Ryde Pinbox
1/77 Armor Bn, 5th Mech, I Corps