Wonderful photography, Wayland.
I was up in Iceland for a few days in mid to late March. It reminded me quite a lot of the Peak district... especially the weather.
There might only be a light scattering of snow on the ground, but all of a sudden, the wind starts blowing force 8 and whips up all the snow as if you were in the middle of a blizzard, and visibility drops to about three to five metres.
There is a website that collects data from sensors along the roads, so you can check conditions before setting out. If the wind gets too strong, I think the threshold is 20 metres per second, buses no longer run... so having your own transport can be essential if you want to see much.