Non joking response.
So Agricola conquers the entirety of Caledonia. After having conquered that, he is ordered to raise a third permanent fleet, the Classis Britannia to try and invade Ireland.
Doesn't matter if he does it or another general the next generation, the British Isles are pacified. Classis Brittania has to guard the entirety of Atlantic and north sea, protecting the trade routes between Britannia and Galiia/Hispania, and the routes between the baltic and Gallia.
The immense cost of having a fleet of oar pulled ships is too great, so a new ship is designed, the Monoreme (think longship).
During one of their anti piracy patrols, the Romans are blown off course on the north sea, and discover the Faeröer. They overnight on the isles. Trying to get back to the continent, they row in the direction of Norway. Blow off course once again, they land on Svalbard.
They plant a flag, claim the barren rock in the name of Rome, and get back home. On the maps its gets the name Hyperborea.
This all needs to happen in the span of about a hunderd years, before the next civil war kicks off. I say its possible. edit: checked the distance between the Faeroer and svalbard. Way too far, maybe in a wank