As mentioned iOS devices do not store any map data (for Google Maps) so without an internet connection via wifi or cellular data network you are not going to get any map downloads to show you where you are even if you have a GPS signal so the device can locate itself.
The only thing you might be able to do is generate a trail of GPS breadcrumbs by taking photos at regular intervals to leave a geotagging trail on your device but this will not be functioning as a live GPS system just a way to review where you have been.
Some of the 3rd party iOS GPS apps may store map data on your device but this could take up to 2GB of space (Garmin Western Europe app is 1.75GB) and the app costs $99.99
Nikkor AF-S DX; 18-105 f/3.5-5.6G VR, 55-300 f/4.5-5.6G VR, 35mm f/1.8G
Speedlight SB-700 http://keystrokesukimages.com