I added a rope light to the sidewall of my trailer (just under the awning) shortly after I bought it. I bought an 18' LED rope lite and several 4' rope light "tracks" at Menard's to hold the the rope lite in place. There's no reason why they wouldn't work on the frame of your rig. The tracks are clear vinyl, and are easily cut to size with heavy scissors or tin snips. They come with double-sided tape already installed, but I found that detergent deteriorated the glue pretty quickly. I replaced the tape after the first year with 3-M outdoor double-sided tape - it has a
red vinyl backer, rather than the white/green paper backer that the indoor only tape has. It's still secure 6 years later. Just to make sure the rope light stayed in the track, I squeezed a bead of clear silicone sealant into the track before inserting the rope light. Also added a glob of clear silicone on top of the rope light, about every foot or so . . . just for good measure. I'd suggest you do the same so you don't end up dragging 20' of rope light down the interstate. If you locate the plug end of the rope light near the door sidewall of your rig, it will be easy to run an outdoor extension chord to your outside 120V receptacle. I added an outdoor timer that I can set to turn them on at dusk and run up to 9 hours (or even dusk-to-dawn) so I don't have to plug/unplug them all the time. It's pretty easy to unplug the extension chord & roll it up for storage at the end of my stay.
You might want to consider it.
P.S. I tried to upload a couple of pics, but my computer isn't cooperating. Sorry!