1

You should expect that the overnight temperature will quite often be as low as 4C and can sometimes be about -2C. Even in the day the temperature can be less than 7C - I remember once having my lunch one day in the far north of the country when the thermometer read 4C, and that was at sealevel, by the coast, in July: hillroads inland of me were probably suffering snowfall at that moment.

This is what the manufacturer says for comfort, but what about you? We are all different in these things. My wife takes an alpine mountaineer's sleeping bag to Iceland, but when I was younger I was happy with just a 2-season. To what minimum temperature are you OK in that sleeping bag, remembering that you are allowed to put on extra clothes on at night if you are feeling cold? And I find one of those very light (60g) metallised plastic "survival blankets" is a very cheap and light way to make yourself a lot warmer in a sleeping bag, I always carry one - they are reusable, and will fit back in their packet after you fold them up. In fact, I usually find if I have been shivering in my bag, it makes me so warm I have to take it off after 30 mins.

2

Thanks iviehoff. If the outside temperature falls in the range of 0°C, I think inside the tent it will be in any case at least 4-5°C warmer, so maybe the 7°C sleeping bag will be fine, with the option of some extra clothing and of the metallic/plastic sheet that I will definitely take with me.
I remember while climbing the Kilimankjaro 2 years ago that when outside temperature was close to -10°C, inside the tent it was 0°C (I had a -5°C sleeping bag, though).

3

Hi,
I agree with previous post. If you need more equipment, just to let you know, you can rent some in Iceland. It might be a cheaper option for you. There are several compagnies which are renting gears : www.backpackers.is and www-iceland-camping-equipment.com for exemple,

Have a great trip