Here is the map for the new Frostfell zone (aka the Ryjesium Mines in Kylong Plains). Name is Frostfell Wonderland's Icy Mines.
Code:
<ImageStyle Name="exp04_dun_kylong_plains_frostfell" displayname="Frostfell Wonderland's Icy Mines" zonerect="-824, -1663, -416, -1189">
<ImageFrame Source="images/maps/map_exp04_dun_kylong_plains_frostfell.dds" SourceRect="0,0,436,506" />
</ImageStyle>