The Garmin GPSMAP 66i is a great navigation device and an emergency communication device. There is a new model, the GPSMAP 67i which has longer battery life and a more accurate GPS system. I personally have not had problems with GPS accuracy on the GPSMAP 66i, so I don’t intend to upgrade anytime soon. I have maps loaded which will allow me to navigate in most situations around the US.
I also have the Garmin Fenix 6X Pro Solar which provides similar accuracy on GPS, but it is much easier to look at the GPSMAP 66i screen.
With an InReach subscription, you can send text messages to cell phones. It may be useless when your contacts are in a disaster situation as well with no cell service, but it does work well if you are hiking and you get injured and require evacuation. It can also send SOS messages which will dispatch emergency services, and can provide GPS position data of your current location for search and rescue.
Make sure to carry a battery bank and the appropriate charging cable.