I'm 70+, and for the last several years almost all my riding (mainly trail riding) has been solo. I always let relatives know my plan and I do take tools (and a flashlight) to do minor repairs or fix a flat. My phone has an app that continuously updates an internet map every few minutes so my friends/relatives can see where I am at any point. I've told them that if they don't see the location move for a while, they should start getting concerned. So far I've never been riding anywhere that did not have cell/data coverage, and I've been way out in the boonies. I also use this feature when I go out geocaching in the car… I can be out all day and cover 250 miles while caching. I have been in some areas while caching that didn't have cell coverage.
I also carry a small external rechargeable battery pack for the phone (which already has an optional double-capacity battery in it), just in case. I've had to use it several times.