CNs for Edge 8xx series units are sold on preloaded microSD cards or you must buy the DVD and transfer your map, I don't know if they are NT or NTU. There is insufficient space on the internal memory.
Edge 1000 and Touring in EU provides preloaded Garmin Cycle Map that is Open Street map and not CN as I know. OSM for cycling are much more detailed then Garmin's City Nav maps + Garmin City Nav maps don't have elevation data at all.
With preloaded maps Edge 1000 has 965 MB free of 7.23 GB.(No courses, no activities loaded)
So for Europe better to use Openfietsmap, more detailed and free too.