Cameras that are not visible are pretty useless other than everyone walking by will wake you up in my opinion. Do you really want that? I have two “fake” cameras on my car trailer that flash a red led all night. I have coach video and can turn it on at my bed if I want ( very rarely do) . I also have a couple motion sensor lights that go on and off all night ! if I leave them on . Very bothersome to other campers but good in a parking lot.
Most threats are drug users looking for a quick score and in larger metro areas. . I stay out of those areas. I also make it so the RV “look” is very clear I’m there and not easy pickings. Like The aforementioned lights and highly visible “fake” cameras
Not knowing where you stop or what your standards for that are , I think you may be a bit to worried about something that won’t happen. BUT since it keeps you up that’s not good . The only thing is to change your stoping / parking habits and stop early in a campground and get a good sleep. Hidden cameras won’t let you sleep better!