Cat in the Arctic

[Northwind]

Hi everyone. Have been visiting this site for quite some time now... what a vast amount of information. Thank you folks so much! First post, here goes.
My wife and I will be purchasing a newer Cat in 2010, or sooner if we find the right boat at the right price. We have three children ages 3, 7, 9, and are planning a circumnavigation in 2014. (want the youngest a little older and a bit more savings in the bank after we buy our boat) Wife and I love the Lagoon 440, but are also strongly considering a Privilege 48 a few years older. Our price range is around $600K ready to sail. Both my wife and I have sailing experience on CA's north coat, but I wouldn't call myself a blue water sailor yet. We have almost no real experience with catamarans, but have decided this design suits are needs as a live-aboard family much better than a monohull.
We currently live in Alaska and would very much like to bring our boat up to keep in Seward the next few years before we depart. We would like to gain sailing experience locally and Prince William Sound is spectacular. Would love to get opinions on owning and sailing a catamaran in the north. I cant say that I have ever seen a sailing cat up here and that is a little disconcerting. There are no cats in seward right now... not one. So I quess that's the question; what concerns should I have about sailing a catamaran up here, and why aren't there any cat owners in Alaska? I have read so many opinions on which cat to buy, but is there one in particular that you would own if you were sailing in North?