I didn't know how those plans work. It seems like a really sensible way to go for someone needing the cell phone only for situations you describe.
I use my mobile phone mostly for work and have upgraded quite a few phones over the years. I've usually given my old phone to someone that can use it for emergency only calls. Not "in service" phones are capable of making 911 calls and I think there are some charity agencies taking old cell phones to distribute to shut ins and needy folks.
I see it as $5 a month insurance.
My husband is looking for another job and that is why I haven't gotten him one...he may get one with the new job. We'll see.