I hope you have a great trip!
I have driven up and down the norwegian coast line several times, even a few times with my Suzuki SJ410. A jumpy little jeep with a very small engine.. so I think your MB SEC will do just fine
At the moment im living on a small farm in Leksvik, just outside Trondheim. If you drive trough Leksvik, perhaps we can meet and fire a few rounds with Luger and drink a few rounds of whisky later on