Although a Norwegian, I had to look this up. The line of succession in Norway is limited to the descendants of the living king, so as a result the list is fairly short with just 7 eligible candidates.

If all those were to die, the Norwegian parliament would (in theory) select a new king or queen. In practice though, I suspect that we'd simply end the monarchy.

This is unlike other monarchies where the line of succession is a bit larger. According to Wikipedia, the line of succession in the UK has more than 5000 entries. [1]

[1] - https://en.wikipedia.org/wiki/Succession_to_the_British_thro...