That requires a subscription plan? Ouch.

I think we need a tiny JS8call transceiver (js8call.com). That is a weak signal ham radio mode similar to FT8, but you can type any messages you like, instead of having a fixed QSO format. Tiny FT8 tranceiver is here: https://hackaday.com/2021/09/25/the-simplest-ft8-transceiver-youll-ever-build/

Basically it is an Altoids sized tranceiver with around $50 of parts, that can send and receive text messages over transcontinental distances, but at very low speed (like several minutes for a 50 character message). It would use a wire antenna a few feet long or preferably longer. For normal use you need a ham license, but in a real emergency saving people takes priority. I have been playing with this idea for a while, but haven't tried to really pursue it.

You could make the tranceiver even smaller and cheaper, by getting rid of the display and just using a phone as a UI and power source. Of course that means you have to bring a phone.