So, my 2nd great-aunt apparently got tested on AncestryDNA and 23andMe and, although she wouldn't have gotten the same results that my great-grandfather would've, it still allows me to get a better insight into what his results might have looked like. I'm not all that surprised based on what I know about my great-grandfather's family.
My great-grandfather's father was from Norway, and his mother was the daughter of Norwegian immigrants. The results below are the results of my 2nd great-aunt:

AncestryDNA:
Norway 93%
Sweden 7%

23andMe:
Northwestern European 99.9%
- Scandinavian 95.1%
- British & Irish 2.9%
- French & German 0.8%
- Broadly Northwestern European 1.1%
Unassigned 0.1%


Now, this might seem like a no-brainer due to their known ancestry, however, my grandfather has tested, and he received a LOT more Swedish than his aunt. Of course, that could be because my great-grandfather inherited more Swedish than his sister, but it could also be that my great-grandmother's (my grandfather's mother) recent English ancestry had quite a bit more Scandinavian ancestry than the paper trail would leave me to believe. For example, here is my grandfather's AncestryDNA results:

Grandfather's DNA:
Norway 52%
Sweden 25%
England, Wales % NW European 21%
Ireland & Scotland 2%

It should also be noted that a good portion of that E,W & NW category most likely belongs to Germany, due to my paper trail and DNA matches.
So, the fact that my grandfather is more than half-Norwegian AND has a lot of Swedish means that his mother does have Scandinavian ancestry. Of course, DNA test results shouldn't be taken as 100% accurate, as they just estimates, but these results give me something new to ponder about.