As long as your horse isn't bothered by the tail bandage, it's fine to leave overnight. The only problem I've ever had with it was with a horse that chewed it off and proudly displayed it all over his stall.
I agree with Jody about the washing. Is there any hot water in the bathroom or something? If not, just make sure she's dry and warm after. You don't want her to catch a chill.
I agree with Jody about the washing. Is there any hot water in the bathroom or something? If not, just make sure she's dry and warm after. You don't want her to catch a chill.