I would say if you are blanketing her, I would at the least make sure she is cool, and mostly dry, and then blanket and let her go. If you have too, use a heavier blanket that night, so she doesn't get chilly as she dries.
I have put a fleece cooler type blanket on mine, along with their normal blanket, as the fleece absorbs the wetness; leave it on them for a few hours and then go back out and strip that one off, refluff and brush her coat, and reblanket as usual. I just don't like leaving them 'wet', but that's personal opinion.
"The ideal horseman has the courage of a lion, the patience of a saint, and the hands of a woman..."