Fenix 5 Plus Iceland maps recommendations

Can anyone recommend some good Icelandic maps that are easy to buy/install for the Fenix 5 Plus series? The Garmin maps are pretty spartan and actually don't provide terribly much in remote areas. Keen to know if anyone has had any good experiences with some of the map services out there. Unfortunately there is no good catalogue showing all the mapping providers which are compatible with the watch, and very little in the way of practical feedback in using those maps.