I've camped in Norway before, and rain is the main motif, if it's summer. I was up in the Lofoten Islands 2 summers ago (didn't get to camp, sadly, oh well), and it rained every day. Not just drizzle, real rain. Don't know about Lapland in Sweden, but if it's above the treeline, that's far North, or high up, ie, it's basically tundra. This past summer in Norway saw almost constant and daily rains, so that's what I would plan on if I were you, ie, wet, swampy, tundra ground, which suggests a real tent floor.
I've camped on the tundra on Hardangervida, was a long time ago, but I have memories that it was a real pain getting just 6 stakes for a doubled hooped tent attached, let alone the many solid stakings you'd need for a mid.
I was curious about this question, and apparently there are some fans of the duomid for that area now, though I wouldn't be one of them based on my experiences in that climate, I want the type of tent that they make there, a double walled, serious, strong, wind shedding tent, like a Terra Nova or Hilleberg, or a Helsport, if you can afford it, which I can't. To me, if you look at the tents made for that climate, they are all made expecting high winds, a lot of constant, and driven, rain, bugs, bugs and more bugs. I guess a Scarp now also would work fine after it was tweaked to work in that type of rainy climate. No need for the cross poles.
Also, in the tundra, it can get really cold, really fast, basically the second the sun goes behind a cloud, it gets cold almost instantly, the air doesn't hold any warmth. With that type of cold I'd want a double walled tent, though I can see making a single walled work if your sleeping bag system is good enough, but seems unpleasant to me to be dealing with cold air blowing through the tent at me at night, I'd rather have a double wall there.
I also wouldn't even consider a tent that doesn't have full bug screening, and bug doors, ie, really, if you look at what works best there, you end up with something like a Helsport, Hilleberg, or Terra Nova. No surprise. But there seems to be some fans now of the true pyramid, though in my opinion, that pyramid needs to have fully integrated bug screens, and a real floor. In fact, heh, sounds like a perfect project for Henry at Tarptents, but the sides of the pyramid would need to go all the way to ground if you needed that.
Clouds of flying things, that's exactly right, if you've never seen it, it's hard to imagine. The joke in the North there is: How do you make a mosquito sandwich? Answer: butter two slices of bread, slap them together. That's not much of an exaggeration, around water sources especially it's stunning to see how bad the mosquitoes/midges/gnats can be.
Oh, and any tent you get should be fully capable of supporting one or two days of unexpected really bad rain, ie, sitting in the tent waiting for the rain to stop.
On the bright side, you might luck out and get really warm nice weather, albeit cold, but you simply cannot count on that up there, you have to assume bad weather and be happy to get good.
Any tent that uses a beak type method (ie, not fully to the ground) to protect against rain I'd immediately remove from your list, rain is just too steady and constant there to use what are essentially 2 season methods.
Wow, I just remembered, when we moved here from Norway, ages ago, my dad had an old canvas norwegian tent, and it was in fact a type of pyramid, except it had 4 arms that folded out to make it sort of boxier on the top part. Of course it had a floor and all that, wooden main pole, but that kind of thing I guess was the old school way there, so maybe Henry really should give this a shot, it's exactly the style he makes already in some ways....