We use BT for our internet. We lose our internet connection perhaps once every couple of months for anything from a few minutes to a couple of hours. We lose our phone line perhaps once every couple of years. We have two elderly people at home with careline and I have a separate hard wired phone in case of emergencies (ignores the DECT system). If we get a loss of internet after the move to IP and the perfect storm happens and we require emergency cover and worse still we aren't at home and the careline is needed, what happens?
I understand the whole "separate power" idea but BT don't have an internet capability that is as good as their telephone one. I would hate to trust emergency calls to who many people regard as not great at internet / IP.
Sadly as they are 92 and 94, I don't think they will be around when the switch happens but others will be in the same boat.