If they can get that to work, what about using Starlink from Elon Musk, basically use WiFi calling via Starlink.
How they do that I have no idea, but if they can get it to work it would certainly be a game changer...
Starlink to offer voice over IP
https://arstechnica.com/information-technology/2021/02/spacex-plans-starlink-phone-service-emergency-backup-and-low-income-access/