Basecamp & City Navigator

My apologies if this is posted elsewhere (or seems rudimentary) but I've searched for this answer and can't find...

In Basecamp, I am not seeing 'City Navigator' as a map choice. I have just 'Global Map'. Note: this is without the GPS connected to my PC.

Is 'City Navigator' available as a map choice when the GPS is connected (my Garmin unit is stored GPS elsewhere so I don't have easy access to it)?

If so, can I then download/copy to my PC so I can plan a route when the GPS unit is not connected?

Also, if I can't 'download/copy' City Navigator and I were to purchase (essentially a second copy) of CN, would this give me the full route planning in Basecamp?