There is no way around the stop-over in Iceland when flying with Icelandair from Europe to the US.
This is a reason for some travelers to avoid this airline, others prefer the pause and the opportunity to walk up and down the long corridor in Keflavik airport. Sometimes the nostalgic thoughts come back from the adventure of the first trip to New York from Luxembourg ... when flying to the US was still a big adventure. http://savvytraveler.publicradio.org/show/features/1999/19990206/postcard.shtml
Every time I see the empty landscape before landing the thought of a longer stop pops up.
Icelandair offers an up to 7 days free stop over which is tempting. Perhaps next summer when the snow is gone and the green moss is visible.
