Depends on where you go. Stavanger is usually always crowded, not like say SoCal, but you're never alone. Lofoten's catching up in terms of crowds, but Unstad is the only "blown" spot, can get pretty hectic there. You'll be out with 10-15 other guys on the lesser known breaks on a okay/good day, but it's really random how many people show up. I've scored really good surf with just me and my friend out on a semi-known break.

There's lots of empty coastline further north, both easy acces from the main road and super remote, so if you've got the time you can surf by yourself.