Careful
As others have said studded tyres are illegal in a lot of countries.
When I was in Norway on/off between 1996-2001 a local then told me that studded tyres I think he said were illegal to use or just about to. That was a while ago so I do not know what the status is now. Best to check.
Further more everyone then seemed to state for grip that modern snow tyres (without studs) were much better for grip than studs. Rubber technology/compounds and tread patterns. Only it seems (from what they were saying) that studs were only better on total sheet ice.
As soon as you get a dusting of snow on the ice then non studded tyres apparently are better.
I have to admit I was amazed at just how fast I was driven as a passenger on the snow and ice ...on snow tyres (without studs).
So from what I have experienced I would not choose to buy a studded snow tyre anyway (unless some particular conditions seemed to make it necessary).
I too have driven across the top of Iceland from one side to the other
It was September and before the snow proper.
Fuel was one of my biggest concerns. In the barren wilderness up there it was hard to know exactly where I was (I do not use/have satnav). Fortunately I managed to identify my exact positions and way points, with the fuel on the right side of my cut off/turning back line.
Big hidden boulders under water in rivers was my other concern. One or two got me!
Incidentally entering Finland via a back road from the Russian border in the far north, I was hijacked by a Subaru Imprezza. Turned out it was the Finnish Border guards.I have photographs showing them opening up the inside of my Citroen 2CV doors; looking for whatever.
Obviously a British Citroen 2CV in the tundra; entering Finland from the Norwegian Russian border in 1996 was too much for them to leave alone.
It was not so long after the Berlin wall had come down after all. I then later in the Baltic republics had to get the car out of those countries on British Embassy "diplomatic" papers following an incident on the Latvian/Russian border.
I took four spare tyres for the Citroen 2CV; and never got a puncture
I just took normal tyres on the 2CV.
Times have changed; Europe is more a walk in the park now. I also saw and witnessed the "fake?" road blocks in Lithuania then. I was warned about them. I just used the 2CV's off road ability to get around them. But just be aware you can potentially have your car partially stripped like I did; if you venture to the east of the tundra!