I flew in there a number of times in the C-141. Permafrost runway. I believe it was RWY 10 but with a very large deviation and we went in true. Had an ILS and they had a controller giving vectors. Can only land one direction. Plenty of ramp space and even could hangar large aircraft. Great billeting and chow hall but I am not sure if the Air Force is still running this with the Danes or not as this was the early 1990s. I used to see SAS DC-10s there all the time.
I second the idea of having the plates and knowing exactly what support is available as you would only be going in there during an emergency and that is not the time to sort it out if they still have all this first rate help and emergency equipment.
Weather can, and does, change wildly and quickly. I always took extreme car with the forecast and carried enough fuel to get back to Sonderstrom which I had to. The had crack forecasters but the conditions in winter are extreme to say the least.
Thule was actually easier to get in and out of however, than Sonderstrom (another alternate). An approach into Sondy brings you down the Fjord and the winds can be tricky. The runway has a VERY noticable peak in it and a C141 was lost there in the late 1980s on a go around due to perception problems. Can circle to land there but only in the day and it requires precise flying due to the really high terrain along the runway.
Also on the 777 and you can just toggle to true if it does not do it automatically above a certain latitude (which I would have to go look up).