FWIW,
https://en.wikipedia.org/wiki/Scandinavia points out:
> In English usage, Scandinavia also sometimes refers to the Scandinavian Peninsula, or to the broader region including Finland and Iceland, which is always known locally as the Nordic countries.
See also:
https://www.dictionary.com/browse/scandinavia?s=t "and sometimes Finland, Island, and the Faeroe Islands".
https://www.merriam-webster.com/dictionary/Scandinavia "Note: Some people also consider Iceland, the Faeroe Islands, and Finland to be part of Scandinavia"
https://www.goodreads.com/book/show/1187923.History_Of_Scand... - "History Of Scandinavia: Norway, Sweden, Denmark, Finland, And Iceland"
https://www.worldcat.org/title/live-work-in-scandinavia-denm... - "Live & work in Scandinavia : Denmark, Finland, Iceland, Norway, Sweden"
https://shop.lonelyplanet.com/products/discover-scandinavia-... - "Discover Scandinavia" travel guide "Coverage Includes: Reykjavik, Southeastern Iceland, the Blue Lagoon and the Golden Circle, Oslo, Norway’s Fjords, Stockholm, Gothenburg, Copenhagen, Tallinn, Estonia, Helsinki, Lakeland (Finland), the Far North and the Arctic Circle, and more"