It's interesting to see use-cases like this "in the wild" (as opposed to some hobbyist group trying stuff out).

With a little investment, I think Meshtastic/Reticulum could do wonders for communities like this. With Argentina being largely flat, even putting up a relatively short mast on the roof of a house should give it a good enough range (~10-30km).

The article is about conventional broadcast, but if two way is interesting, there’s a great project doing digital over HF in rural areas, particularly South America:

https://www.rhizomatica.org/what-we-do/

Lightweight HF rigs and the Hermes Mercury digital modem:

https://mercury.hermes.radio/

There is already a group of people working on meshtastic: https://mesharg.com.ar/ with an active telegram group.