I can guarantee that Google records your location even if you're out in the boonies, completely out of a cell coverage area.
You can check it yourself if you're an Android user. On a PC:
Google Maps > Menu > Your Timeline
Pick an old location you visited (red dot) where you know you were in a sketchy coverage area (or had to drive through an area of no-coverage to get there).
Clicking the dot will take you to the day you visited that area.
In the bottom right, click on the settings (gear icon) and select "Show Raw Data"
You'll see a consistent trail of GPS bread crumbs right through the spotty or nonexistent cell zones.
My point being, it's not the cell phone transmitting that matters -- it'll buffer and "catch up" at a later time when it's connected. If you want to be invisible, you have to mask the GPS receiver (and actually WiFi and cellular too, unless those location services are user-disabled inside the Android settings) because it uses a combination of sources to determine the device's location).