We used an inReach communicator when my daughter was in the boonies in Bolivia. There was a health issue involved with one in the group and the communicator is just about one step better than morse code nor did if feel like it was all that reliable to me. For that sort of application where she needed to have her position tracked and for communication in an emergency, it worked ok and did what we needed it to do. There is a LOT of latency to the messages - it takes a long time for a message to go up, come down to the unit and then the response to come back. And it's pretty expensive too - a satellite phone might have been more functional. I'm not sure that inReach is a great option for poor cell phone coverage. I'd view it as a last resort as in be prepared to spend a lot of time waiting to coordinate rescue. If you're in an area that is accessible by motor vehicle, you might be just as well off having someone come look for you on your route when you don't get back by a particular time.
My view, after using this, is that the perfect application for this is being in very remote wilderness areas that are not easily accessible, being in lightly populated areas of third world countries, or at sea. We were in the second of those use cases and it was still borderline marginal.
Something to look into might be UHF (ham radio) repeaters. I was looking at some tiny UHF radios for a bike tour with a group and one of the videos I was watching, the ham demonstrated hitting repeaters at significant distances. Be worth looking into where you'll be riding and the repeater coverage. Getting a ham license now that the morse code requirement is gone, isn't all that hard. I'm not an amateur radio operator but I did find this
website that shows the availability of repeaters by state. Might be worth checking into - maybe find a ham that could help you with that.