Thankfully, I just happened to get my acceptance mail this morning from Tromsø, too, so I said yes to them today at 12 o'clock already! :D Now I have to get some complicated stuff sorted out because it's at another institute, but I totally have a place in Tromsø! :D
And I think what you suggested would have been what I had done, hadn't the Tromsø people answered so fast, but this way, now it's easier of there are any people who want to go to Bergen and initially didn't get a place. :)

So excited! :D