Other European Frequent Flyer Programs - Pay to upgrade at check-in on Icelandair?

For an upcoming trip on Icelandair, the ticket is for regular Economy.

Is there a way to pay for an upgrade to Economy Comfort or Saga Class, either by paying cash in advance or at check-in, or possibly using another airline's miles?

I would guess that using miles isn't an option, and the Icelandair website didn't have any info about upgrading with cash.

Thanks!

Just back from 4 flights on FI (BOS/KEF, KEF/AMS, ARN/KEF, KEF/BOS), and every flight was 100% sold out, so no announcements or other info was available about upgrades, either for purchase or otherwise.

I can vouch for the roominess of the two exit rows, though. They were rows 16 and 17 on all 4 of our flights.

16 does not recline, but has normal seatback entertainment and tray table. 17 does recline, but has pull up entertainment (quite annoying) and tray table in the arm rest.

I've heard this isn't an option unless you pay the fare difference.

I should add that while waiting at KEF for flights, I never heard them announce any upgrade options on other flights being called. They were trying to get 2 people off of a flight to MSP, as it was oversold. Offered $500 USD along with a "free layover" of one night at a hotel in Reyjkavik, with transfers, hotel, and meals paid by the airline.

Thanks!

I should add that while waiting at KEF for flights, I never heard them announce any upgrade options on other flights being called.

Icelandair has pretty good load management, so I don't see a lot of upgrade...

But I have gotten some pretty good offers for upgrading when checking in at BOS->KEF->LHR, like $300 for Saga class.

They were trying to get 2 people off of a flight to MSP, as it was oversold. Offered $500 USD along with a "free layover" of one night at a hotel in Reyjkavik, with transfers, hotel, and meals paid by the airline.

I've taken them up on this more than once on returning from LHR to BOS. In several cases it's resulted in a near-zero cost itinerary for me.