Cell service is poor to non-existent in the wilderness areas around my parts.
I’m not getting far out into the real wilderness around here but twisting an ankle a couple of miles from the road could be a problem.
Now that is going a long time without female companionship!
A few years back in the Great Smoky Mountains NP a 5th grader summoned park rangers with a hand held HAM Radio. A classmate drowned at a water fall on a school field trip. The HAM as near the 144MHZ spctrum I think. A cell is 800HZ..
The smartest way to use a cell phone in limited reception area is texting. It takes a fraction of the time, conserves battery, and is far more likely to be picked up especially if several text are sent. Send any helpfull information such as I am near a creek, I see a nearby field {go to it if it can be reached safely}, and any other landmarks you see. Once that info is sent? Stay put. Panic kills by causing bad decessions and waste precious body energy.
I recall a case of a family getting stuck in the snow on a forest service road in Oregon. I believe that their location was narrowed down by the signals received from their cell phone, even though there was insufficient signal to actually make a call.
Some years ago I was driving up a hill in northern California with my two-meter ham rig on. I ended up having a brief conversation with another ham who was transmitting with a handheld radio from the top of Half-Dome in Yosemite. If you can get some elevation that will get you some distance.