How does a Contract for Deed work in MN? Is it right for my situation?

I've rented a converted den from a little old lady for about 7 years now. She's getting up there in years and I like the house and location so much that when she pes I'd like to move into the rest of the house instead of moving on. Is there any precedent for a CfD that starts out paying the owner, while owner and buyer are under the same roof no less, then switches to paying the heirs when the owner pes?