Apologies for the confusion - what I was clumsily trying to bring across was that while all of Norway is in GMT+1, the westernmost parts ought really be in the same zone as the UK, seeing as we're at 6E or so.
Worse for the people up north, though - the town of Kirkenes right next to our border with Russia is actually east of Istanbul. They, too, are in GMT+1.
Happy New Year to all - let's hope 2023 proves less eventful than 2022 was (for all the wrong reasons)