I can imagine how distressing this would be for the owners. Never store anything you love outside.
My plane needs new paint and I use a canopy cover when traveling but it still bothers me when the plane is outside overnight. I see my ownership as being the caretaker of something that has already lasted a long time, because others took care of it, and therefore I have an obligation to do the same. I wouldn’t own a plane if it spent every night outside, not because it is wrong (it isn’t) but because I wouldn’t be at all happy if I failed in passing it on someday in nicer condition than I acquired it. Financial loss, insurance etc is not the main issue for me.
Never store anything you love outside.
Unfortunately my old Super Cub got mangled when a hangar collapsed in a storm in 2020, but got repaired.
Moral being put the airplane in a well built hangar. I certainly am a believer in hangars, well worth the expense.