Internet isn't available everywhere, and, as you're traveling off-road, make sure that your map is accessible even if you don't have phone service.
In the Settings -> Load Map section you'll be able to download the part of the map that you need to always have access to.
Select the specific area you'll need for your trip on the map. In the upper right you'll see your chosen map's size in Kb, Mb, or Gb. Press Load .
As soon as the map loads, it'll appear in your list and you'll be able to confidently take off on your off-road adventure with no internet access.