Phil:
Radisson has in the past offered some select non-formal cruises in the Caribbean. However, I know of none so scheduled at the moment. Wish they'd have more non-formal sailings, as it seems that the ratio of formal to non-formal sailings is much higher than customer preference would dictate, according to any "straw poll" I've seen on this subject.
Been to Alaska --- never Greenland, but I've seen pictures. Though they are both in northern areas, there are a lot of differences --- enough to make Alaska a good destination (even for you). The temperatures there are rather nice in the summer.
Thanks,
Richard :) :) :)