Most of the winter road does not have cellular network coverage but if you have access to a Wi-Fi hotspot you can still call or text with WiFi calling. Not all devices or mobile network operators support Wi-Fi calling.
Here is how to enable Wi-Fi calling on Android and iOS:
Android
- Open the Phone app .
- Tap More Settings.
- Tap Calls.
- Tap Wi-Fi calling. If you don’t see this option, it’s because your carrier or phone doesn’t support this feature.
For more information read here:
https://support.google.com/phoneapp/answer/2811843?hl=en
iOS
- Turn on Wi-Fi calling in Settings > Phone > Wi-Fi Calling. You might need to enter or confirm your address for emergency services.*
- If Wi-Fi Calling is available, you’ll see Wi-Fi after your carrier name in the status bar. Then your calls will use Wi-Fi Calling.
For more information read here:
https://support.apple.com/en-us/HT203032
Consult your cellular network provider for any further support.