Finnair, Norwegian and Icelandair all had rather forgettable off-peak fourth quarters, but not because of the chilly weather they are all enduring. Rather, each has a unique set of challenges and opportunities. Finnair’s challenges include exposure to Asia and transatlantic competition, but there’s hope in seat densification. Norwegian is painfully exposed to Norway’s struggling oil industry, but they have a grow-baby-grow strategy. And Icelandair is perhaps doing the most with less. After all, the airline has never had a profitable fourth quarter until 2015. Icelandair has managed to get a good portion of its revenues in strong-currency countries and keep its costs in a weak-currency country. Hint: That’s a good thing. We also consider Spirit’s ticket revenue pressures and how Hawaiian is handling an up-and-down Japanese yen.