As others have said, one ways will always be on the expensive side. Is it worth booking a return with the aim of coming back at Thanksgiving or Christmas? As LondonElite says, getting a changeable fare would also help.

Airline wise, can't speak for Icelandair but Aer Lingus' new business class is pretty good and offers decent solo window seats in a staggered formation. You need to book the right flight numbers for this though, and note that it flies the new J to limited destinations.