The most apparent geothermal areas in Greenland are found around Scoresbysund. Considering the second layer of convection rolls, the areas in Greenland are found as a continuation of the volcanically and geothermally active zones of Iceland. No one expects underlying connection in that direction, because the upper most convection rolls mark the main trend of tectonic alignment in Iceland. In this way, the exceptional activity level in Iceland makes itself felt in Greenland too.
The basic map showing geothermal springs in Greenland is from https://www.geothermal-energy.org/pdf/IGAstandard/WGC/2010/0158.pdf.
The numbered convection rolls are leading to: 1) West Volcanic Zone, 2) Mid Iceland Belt, 3) East Volcanic Zone, 4) North Volcanic Zone.
The geothemal areas at Disko are subject to similar effect, being exactly 30° farther to the west. The area is much older, and the main division line there is weaker, as the rifting process of Baffin Bay ceased a long time ago, which is explained here: https://en.wikipedia.org/wiki/Canadian_Arctic_Rift_System.