We love Christmas in Iceland. We did already a few years ago and loved it. The highlight was probably the ice caves at Vatnajökull park/glacier. They melt every year then reform in winter so allegedly they're never the same; I think we'll test that! We'll probably also do some version of the Golden Circle tour plus some lava tubes. Then spend time in Reykjavik. We only have 4.5 days. It's a direct 6hr flight from our airport, and one can now book Iceland Air with Alaska miles.
Yes, staying at the EDITION: first two nights on FHR credits (one on each of our Plats, still had to pay ~$300 per night after credits). Then last two nights using The Edit credit plus 55K URs (point boost so at least it was 2x value). I'm not too happy about the price, but it's Christmas so anywhere will be expensive and I guess I'm glad to be knocking out some of these new hotel credits, so many coupons...
I'm reading your trip report and now I'm worried that room charges will get messy at checkout. I just hope we can stay in the same room all 4 nights despite having 3 reservations. The Parliament Hotel is also on Amex as part of the Hotel Collection so needs 2-night bookings; I've been wondering if we should switch to that hotel and just use the FHR credits.