You likely know about the earthquakes and such in Iceland, just be aware that if there's an eruption it will mess up air travel real good like it did last time. Have a backup plan or two ready.
And just about every flight from the US to Europe flies over that part of the world. When I left Germany the hostilities in Israel had just started and it sure looked on the fight tracker like they swerved to avoid it, which is good. But then of course we headed over to Iceland and Greenland.