Yesterday we returned from a few days in Iceland.
Temps along the South coast varied from the low 50s to just above freezing. Daytime temps were in the 40s most of the time.
Altitude makes a huge difference, with colder temps and snow increasing as you move inland into the hills.
It was rainy with low clouds and winds of 20-30 mph, and occasionally higher. We saw winds of 30-40 mph at Keflavik airport yesterday afternoon. Occasionally skies would partially clear.
We didn't see many caravans (trailers), but those we did see were a little larger than the typical European caravan. I don't recall seeing any Class Cs, but no doubt there are some.
Seems like the thing to have would be a heavily insulated, off-road engineered, self-contained vehicle. Once off teh few paved roads it's a harsh place.
Crossing the ridge East of Reykjavik in the ring road yesterday morning we were in a light snowstorm almost the whole way.
Back again, Iceland is just an Incredible place. Very diverse terrain, weather, areas are very similar to Ireland. Rving in my pinion is the only way to see this country.
Next time would have to go with a 4x4 rig to get to the interior areas. Not sure if we just go lucky, but temps averaged 45+-55+, Not to crowded & even got to see the Northern light twice! Only down side is the expense, everything is VERY expensive!
If you get the chance this a highly recommend trip!