We should also remember that, although second generation muslim women on average tend to have fewer children than their immigrant parents (though still many more than european women), muslim women who espouse stronger religious views are the ones that have the higher fertility rates, and continue to marry at a much younger ages, further enhancing the effect of their higher fertility rate. In other words, there may actually be some tendancy for a muslim community to become more radicalized over several generations, as the ones that are more open to integration do not contribute as much to the total growth. If I had it my way, I would make all immigrants take an oath (to Allah or whatever other god they believed in) before they were allowed into my country, that they would not refuse to use condoms and birthcontrol pills !
The best way for your people is looking for a new country because the entirely Scandinavian is already lost to Muslims.