Official comment
There are a few ways to do this.
You can save the mission and if you have the Base or Pro subscription it will download an offline basemap. That might be slightly different from the standard Apple Maps version.
You can import your own data from ArcGIS or Mapbox as the data source.
These links are for the older version of Map Pilot but the process is the same in Map Pilot Pro.
https://support.dronesmadeeasy.com/hc/en-us/articles/115000168726-3rd-Party-Basemap-Mapbox-Share-URL
Or you could fly a overview map in Map Pilot Pro, process it in Maps Made Easy and then use the colorized DEM as the source for your layout. This might give you enough landmarks to go from.
Or you can create a quick markup KML file in Google Earth or some other source to use as a guideline for your layouts.