I need advice on my totalled yet still beautiful baby.

Elijah - I don't know of any insurance company that would have anything to do with the covering of the RV. It's not the insurance company's responsibility to tell the repair shop (or you) to cover the RV in case of rain. When the RV is in YOUR possession, it is YOUR responsibility; when the RV is in the repair shop's possession, then it is a combined responsibility between you and the repair shop.

If it sat in your possession for 3.5 weeks, then why didn't you put it back in the barn during that time? I get maybe one night because you thought the insurance guy would be back, but when he didn't show the next day, you should have taken control and protected your possession.