freezing temps on Thursday

You don't need to do all that just for temps barely reaching freezing. Will you have some heat on in the RV? That will be plenty to prevent any issues. And for that matter, just your water tank and plumbing being inside prevents freezing drastically, even without heat on. You don't have to worry about that stuff until you get down around 10-20 degrees that's when stuff gets real. Even then, worse case is your pipes against the wall might freeze up if you don't keep them exposed to the inner RV air (i.e. not covered up by drawers etc).