SynMat HL Winter

I don't know the weight of the Exped you listed, but you are right about the website weights of the vendors. I do have an older R=5.2 Exped SynMat Winter HL in medium wide that weighs 539 g. Here is a photo of it rolled up: [https://imgur.com/a/SZs4DAy](https://imgur.com/a/SZs4DAy) And a photo of it in a tent with another pad: [https://imgur.com/a/F4cSV7j](https://imgur.com/a/F4cSV7j) I recommend a WIDE mummy pad. Your listed sizes suggest that those pads are not wide and other numbers seem off to me, too. Probably you might need to see the m in person.

What time of year are you going? I've done a lot of camping in Iceland in a range of seasons over the course of about 7 trips, if you're going in summer you don't need anything particularly large, just think UK spring or Autumn really. I took a Synmat in May/June and it was fine. All I would say is that it's very windy and there are very few trees or vegetation so your tent needs to be able to stand up to the wind exceptionally well. I stayed at a campsite on the south cost where someone's tent literally blew away with about half their stuff in. It ended up in the sea. So get good pegs. The ground isn't very soily! Definitely take a ground sheet protector there's some spikey rocks.