I've used this for putting to the side of my van door. If the back side of the van is facing the woods or whatever cover there is, when you open the door, you're then covered on all sides, basically. A quick dash & you're in the 'bathroom'. You could always tie one or both of the ropes to the trailer, with screw in ring to tie it to. (can't think of the right name for it - I'm over 50, that's close enough!) Clothespin a big towel to it & you've got a pretty nice sight blocker. Or, just buy a hunk of fabric that you'd cut in a diagonal shape to clothespin to fit. To weigh it down, you can sew a simple hem & use a dowel rod in the little pocket. If you don't sew, there is fabric glue &/or 'stich witchery' tape that is melted by your iron. Just fold the fabric up an inch or so, lay some of the iron on tape stuff on & iron per directions. Anyone can do that!
You can see inside this one that there are net shelves for bath items, wash cloths & such. Several net pockets too. I put the porta potty in there & there's still plenty of room for items you want to keep under cover. If there's going to be a big storm & you want everything put away, just put it in the shower area overnight when you're not going to use the shower. Sure keeps the charcoal dry! These use a solar shower bag & darned if they aren't great!
When all else fails, keep a towel to wrap around you & make a dash to the tent! If you've been drinking, once you reach the invisible stage, it won't matter!
I drink caffiene free Pepsi, so no, I haven't tried that! But here, you can! 