The four jurisdictions in North America's far north all are. Nunavut's the largest, followed by Alaska and NWT. Only Yukon's a moderate size - a little larger than California (with 0.1% the population).
Seattle is not the capital of anything. Olympia is the capital of Washington (I should know, I was born there) and Washington, DC is the capital of the United States
First of all, I only got Columbus with one second left - I was surprised it made the list. In checking the conditions (needs to touch a Canadian point on land), it's actually even closer than what's listed. From the dot for Columbus on Google Earth, I've got 123 miles to the southern tip of Pelee Island.