Or use an alternative like OsmAnd Maps or Magic Earth that have great CarPlay support, use open and detailed maps, and allow you to offline the entire planet should you need to.

I seem to recall hearing that if you ask for directions to an area with poor cellular coverage, you will get a prompt asking you if you would like to download the map.

Haven’t tested it myself, but nice touch if true.

Nice! This is one of the few features I miss from my old Lumia.