As far as I can tell,any tracking apps for your phone will not work if you do not have a cell signal.
I've been using a SPOT tracker for years on my motorcycle,as I often find myself in places with no cell signal
https://www.findmespot.com/en/
I have the 1st generation that still does everything I need.There are newer versions available.
Service is 149.00/year
you can set it to track automatically or you can do it manually whenever you want.
I usually push the button whenever I turn on to a new road.
It can be sent to send your position via text and/or post it on a web site or even Facebook.
They also have a 911 button that will send emergency services based on the tracker location,as well as an option to send a fixed text message.