Buying your parent's house

Both my parents and my mother in law are worried that they will lose their houses if they have to go into a nursing home. Would the following scenario work? My wife and I purchase both homes with seller financing and they(both my parents and my mother in law) then rent the house back for the same amount of the mortgage payment. My only other question is what happens upon their deaths?

We covered this on the Podcast today. Wednesday, November 20th. It will be live in the next 3-4 days. Thank you so. much for listening. Mark and Mat