Cell Phones . . .

 ... Could this work?

How to Turn Your Android or iPhone Smartphone Into A Satellite Phone
https://www.askaprepper.com/how-to-turn-your-android-or-iphone-smartphone-into-a-satellite-phone/?utm_source=newsletter&utm_medium=AAP

  To maximize your chances of survival in a crisis you need to be able to keep in touch with others. That lets you share knowledge, ask for help when you need it, and keep each other informed of approaching threats. Unfortunately, our modern communications network will be one of the first things to go down in a real crisis.

(SNIP) ... Luckily, there’s a solution – satellite phones. A modern satellite phone has all the capabilities of a cell phone, but it doesn’t rely on towers that can be demolished by the wind or disabled when the power goes out.   ---CONTINUED---

That article is talking about a specific set of products that only work with older smartphones because they are cases that wrap around your device.

Better options exist, like the Iridium Go! box which allows you to connect up to 5 devices to the Iridium LEO network, although I have no idea of cost or throughput. But it does claim to do text messaging and voice calling as well as data connections through their app.

Product page: https://www.iridium.com/products/iridium-go/

That said, if an event is large enough to take down both cell service and landlines in your area, any help might be further away than is useful. Of course having comms would let you contact folks outside the event that you're ok or that you need something, but I wonder how many people in an area have satellite phones - and do first responders have access to them?

I haven't prioritized comms in my prepping plans (just have some packs of walkie talkies and enough batteries and chargers to keep them running.) But eventually I was going to get a Ham Radio setup that can run off batteries and solar panels since I expect that more folks have Ham equipment than satellite gear (although that may change once Starlink and the other competing broadband satellite systems go into service in the next few years.)

How To Charge Your Phone When There Is No Electricity
https://www.askaprepper.com/how-to-charge-your-phone-when-there-is-no-electricity/

  What would you do if the power is out and your phone battery is dead, but someone’s life depends on you being able to make a call?

You can charge your phone from another battery.   ---CONTINUED---