I think this could be doable, the only problem is that you are introducing an extra failure point (i.e. watch works, support device is down/battery dead/unable/

I think this could be doable, the only problem is that you are introducing an extra failure point (i.e. watch works, support device is down/battery dead/unable/ to connect to Internet/outside of wifi range) and if I have to choose between "data privacy" and "I had a stroke and need medical care" I'd go for the latter.