I would guess that a modern equivalent of that German family will have a mobile phone with them. And my instinct is that SDR makes it practical for phones to be able to become 406MHz COSPAS-SARSAT beacons when they need to not far in the future.

A 406MHz beacon is going to be relevant to a lot of scenarios that people get into in large sparsely populated countries like the US or Australia, because it means somebody knows where you are and that you need help, and then all they've got to do is come help you.