Sorry for the rant, but hopefully this saves folks some trouble.
I have flown Icelandair multiple times to Europe due to the good prices, and it was nice to have the required layover in Iceland to stretch my legs. Keflavik Airport in Iceland is... well... hectic and a bit cramped. Friends of mine who travel to the EU more frequently warned me against it, but I had never missed a connecting flight and gotten stuck in Iceland... until yesterday.
Let me warn you that being stuck here isn't fun. Keflavik Airport starts shutting down around 5 pm local time after the connecting flights clear out. Getting help from Icelandair staff is extremely difficult. They just are used to stranded travelers milling about here and don't seem to care.
Thankfully, other stranded travelers and I found a "meeting area" at the airport exit from where we were --- without any actual instruction --- just sort of thrown on a bus, rushed to the back room of a restaurant where we were given a few minutes to eat the remains of a buffet meal away from the rest of the restaurant customers, and then dumped at a hotel about an hour away. The hotel staff had no idea they were going to have dozens of stranded passengers walk in, but they assured us that it happens regularly and they were kind and accomodating. Luckily, I was first in line and I was able to access the Wifi for a self check-in process. Guests further back in line were not able to get rooms and were bussed somewhere else.
That said, it is very hard to find out what is going on. The best I can tell is that Icelandair pays hotels in the west of Iceland some sort of voucher to feed and house stranded travelers. A store clerk told me I was very lucky to have found lodging and food for the night, as hotels here book up quickly and stranded passengers sleep on the floor at the airport regularly.
Today, I will try to find out how to get back to the airport and find how to file for potential reimbursement.
This whole process has been very stressful.
I can honestly recommend that you reconsider Icelandair to Europe, unless you are doing Iceland itself. I understand that Icelanders are quite proud of Icelandair, understandably so! I have flown them several times without incident. But, the more often you fly with them to mainland Europe, the better the chances are that you will be stranded here virtually without help. Please consider a direct flight or get a connecting flight at a busier airport with actual backup options!
I am sorry to have to make this post. And, please don't think of this as bashing Icelandair or Iceland.