I've been along the shoreline of James Bay, a couple times. I have friends in the north, including Churchill, MB. and have worked in a couple places up there.
No roads to trailer a boat to James Bay or Hudson Bay, unless you tow it there in winter on a winter road. There is a rail line to Churchill, MB. but it is damaged and reportedly being repaired "soonish" by Omintrax. You could probably ship the boat there via rail. Otherwise you need to sail the NW Passage or over the top Quebec, to get there.
LOTS of bugs in some locations. Very short season.
The lack of accurate charts in the north is a big concern for the Canadian SAR crews tasked with saving naive non-locals, and passengers on cruise ships, who are starting to consider this as a good place to go.
Even with the Arctic Rangers, they don't have enough resources to cover the whole area, let alone rescue a load of cruise ship passengers.
Many people have no idea what they are getting into, and the problem of dealing with things if it goes wrong.
It's a place you need to be completely self contained and prepared. If you are lucky, it all goes well. If it goes bad, it can really bad. Unless you are near one of the far flung villages, assume you won't get help for a long time, if you run into trouble.
I plan on sailing there one day. It's one of many reasons I want a steel boat.
I'm comfortable being in true wilderness, and love the solitude and challenge.
It wouldn't be in a fibreglass boat unless it was camping/sailing a Wayfarer or a Hobie along the coast (which i have also long considered)