It looks like almost a Blue Gem (see link below) :)

Not the most cold hardy of the ones I have here. It seems to get damaged below -5ºC, with cases of severe defoliation but good recovery and good flowering the next year if generously aided with fertiliser. I use it as extra thermometer :)

A list of what Hebe are growing well in Stavanger Bot Hage could give hints on what the microclimate is like and maybe help to add further hardy species to the area, but it seems to be one of the mildest areas of Norway (and Scandinavia for the matter) and have quite similar climate to parts of Britain or NZ. Hebe do not seem to go under -10ºC in NZ. But if you hear of any Hebe growing around Trondheim, now that would be quite neat :) It was already nice knowing they grow in Shetland!!