In travelling the world, the need for communications seems to have shifted away from cell phones in a lot of underdeveloped areas entirely. WiFi rules, and has made everyone accessible with it for voice and text. People get a phone, pop in a chip for identity, and never use the GSM or CDMA bands at all.
Everyone outside of US and Canada has WhatsApp or Wechat. Europe. Africa. SE Asia. Everywhere south of the border. Most of them will never touch a cellular network ever. The companies know this and charge astounding amounts for texts and voice.
When I travel, and increasingly in the US, I use WhatsApp, Vonage, Wechat, or other methods to seamlessly communicate via voice, text, or "walky talkie" recorded message. I communicate a lot in other languages, and not being as fluent in some of them is no sweat. There are extensions to correct my terrible Mandarin or completely translate from English, Spanish, French, Italian, German, or any other language I might use into acceptable Mandarin, Tagalog, etc.
The point is...it's all wifi. It's relevant because I use a $400 ubiquiti backhaul system to drag 100 kbs internet to my home from 14 miles away. I also have cellular access, but use it less and less since the services listed above have eclipsed the cellular service for convenience and quality even though I live in a tech hotspot.
If you can tap in to decent wifi remotely, beam it to your remote place, you've got it made already. You won't look back. Tell your contacts to use WhatsApp or one of the other services. It's encrypted. It's better. It's more convenient.