Well my back up plan is my cell phone, I would suggest that you look for a company that is offering some sort of emergency service as some of them now are.
I was not aware that you can not make emergency calls, where does it say this on these plans? The small print? I am not sure what I would do either because we can not get cell phone reception as we are in the woods.
I think that vonage is one of the companies that is now offering a package that you can actually make emergency calls on. I have to check into this further but it really doesn't matter as my cell phone does get a signal.