First thing you need to look at, if you haven't, is road maps to see where you can actually drive. I've camped for years in both remote and vehicle accessible bear country (not polar) and had plenty of interaction, and I would assure your wife that the danger from bears in boon-docking is pretty minimal if you take the well-publicized precautions. Mainly keeping your site clean, don't leave food, garbage, and cooking equipment out. I wouldn't bother with an electric fence. When under canvas in remote areas it used to be S.O.P. to stash a rifle away from the tent in case you came home to a disagreement over occupancy, but generally if there was an issue it was over and done before we got there. Bit of cleanup and tent-sewing. Not an issue at all with your steel walls. If you're hiking, try not to surprise a bear, and always travel with someone who can't run as fast as you. You'll be a bit early for ice-fishing but there's still plenty of unique things to see and do in Canada's arctic. If polar bears are on the must see, I second Glasseye's Churchill recommendation. You could also look at the Nunavut tourism web site. There are polar bear web cams in the Churchill area. Yellowknife is OK, but it is pretty much end of the road and you might find the Alaska Highway offers more scope. There are plenty of folks on the forum who have gone before and can answer questions and offer advice.