I have carried two cellular devices for several years because of problems like the aforementioned. One on the "V" network and another on a network that features a push to talk type service. Both have advantages and disadvantages noted as I have traveled across the southeastern US and beyond. I am a licensed amateur (ham) as well and the largest problems noted isn't the availability of the repeaters, but the availability of people listening. As an example, I attempt to make contact with the local hams on local repeaters as I travel to new or even familiar areas, often times to no avail. The repeaters are up and listening, but no one else seems to be. However, I will continue this because I realize that when stuff happens, Ham radio may be all thats left. Been there, seen that. Additionally, learning the necessary skills and technical information to pass the test makes one aware of the proximity of amateur frequencies to public safety bands that are monitored continually. In a life or death situation, "ya do what ya gotta do". Bottom line is that there is no one "best fix" for everyone, and no system is perfect.
Forever... A long time to be dead!
Staunch advocate of the First, Second, and Fourth Amendments