I didn't know the Launderettes--looking forward to exploring their music.
The only Norwegian musicians I know are
* The Kings of Convenience (including Erlend Oye's spinoff band The Whitest Boy Alive)
* Ane Brun (whose song "Don't Leave" appeared on a Superbowl commercial a few years ago; she was the most Googled term during that game)
* Rebekka Karijord, whose haunting "Wear It Like a Crown" is one of my favorites: https://youtu.be/XuBJ0QQ4dak
All the above are highly recommended.
In my limited experience, Norwegian music is a bit more sober and less ironic than Swede Pop but still upbeat. Danish music is more melancholy (doh!). I don't have a clear concept of Finnish music. Here's Anna Jarvinen (a Finn who lives in Sweden and records mostly in Swedish) singing in German: https://youtu.be/gPSRgZM2n5U
And about all I know about Icelandic music is that there is more to it than Bjork and Mum.
Thus endeth the Scandi-pop lesson.
Enjoy your weekend!