This just popped up on hacker news today, could be yet another viable option.
From the short article:
Kuo: iPhone 13 to support LEO satellite communication, allowing users to make phone calls and send texts without cell signal - 9to5Mac
The iPhone 12 has been a massive sales hit for Apple thanks to the launch of 5G. It seems Apple...
9to5mac.com
From the short article:
upcoming iPhone 13 models to feature a low-earth-orbit (LEO) satellite communication mode. This would allow an iPhone 13 user to send messages and make phone calls, even when they are not within standard 4G/5G cell tower coverage.