I would be helping her fix the leaks and encouraging her though I would be hoping she stays the entire time. There are some who do camp/live in those temps without heat or power, just what one can tolerate.
I like the idea of her staying a couple of nights either on the driveway or at least nearby. If not on your driveway, possibly a friend (even if it's her friend) so she doesn't feel like she is being watched.
Biggest concern I would have is if she is financially aware and has those things figured out. Hopefully she has worked out a budget figuring where the money is coming from and where it's going. Gas, insurance, taxes, maintenance, food etc.
Another good thing for her to do is have a safety person. This is someone who she will check into with on a regular basis, usually daily. She should also let them know her next couple days of plans. Most of the time, this should be done by calling them as text messages can be easily faked from reviewing old text. And you need to know who the safety person is. This way someone is keeping an eye out just in case some thing happens, they can get hold of you.
If she has money sense, doesn't mind the cold, etc, I don't see a problem with it. Doesn't mean I would like it, but I would support it.
Wish you and her luck.
