The 15 ft panel to controller distance with a portable, aimable panel is a difficulty unless you can put the panel on the roof of the RV.
You need the panel on the south side of the RV and even then you are limited to 180 degrees if that. The sun goes around more than that (46 degrees more on 21 June) so the trailer is blocking off the sun part of the time.
It is even worse if you have the panel near one end of the trailer with awning and slide sticking out. You have to switch sides or ends where the panel is at some time during the day. Except you might need to put it in your neighbour's site to achieve this.
It all gets complicated depending on your options at the site, but in general for a ground mounting and a 30ft long trailer, you need to get that panel much farther away from the trailer than 15 ft. I find 35ft is restrictive but doable where we camp.
As mentioned , you can avoid all that trouble by placing your portable panel up on the roof so it can see all around, but now you have other issues to contend with. (contraption time! :) )
