I know a lot about Vancouver Island, I have been all over.
Port Hardy is at the end of the road and there is not that much up there that I am aware of in terms of ready to reach land destinations.
In addition the west coast of Vancouver Island is very much wilderness and you can't drive down that side. The west coast is rocky and stormy and it is definitely not a particularly safe or pleasant place to take a boat.
All of the great attractions at Pt Hardy are based on the water, and there is a lot to see there. You can boat safely from there and there are a lot of channels and islands. For the most part boating up there is pretty safe, but you should check the currents and weather forecast and get local advice.
I would suggest looking into chartering a boat for another day or two and doing some cruising around up there. There are a lot of marine mammals all through the islands as well as all sorts of sea birds.
There is a particular place, Nakwato Rapids, that is quite remarkable. It is across the channel to the north on the mainland side. It is famous for having the most extreme currents in the world. At max ebb currents have gotten as strong as 16 knots.
For years I used to go and stay at a dive resort up there called God's Pocket. We would drive up, leave our car in Port Hardy and get a boat ride out to the "resort" which was a small place on a small island about 12 miles from Port Hardy. The place was nothing but some rooms for sleeping, a short boardwalk, a room where we hung out between dives and a galley where they served meals.
We went out twice a day by boat to dive and it was the most amazing place for diving. Great visibility and abundant life, kind of like an underwater rain forest.
We explored all around there by boat. Eagles everywhere, I think I saw several dozen just hanging out at one location.
If you had the time you could take a ferry from Port Hardy to Prince Rupert, the boat goes up a lot of inner channels and it is quite a lot of wilderness. Not many people live up there and there are no roads into that area.
There is marvelous boating to the south across from Campbell River, a place called Desolation Sound. It is a favorite cruising destination, for years I used to go there every summer by sailboat.
Look for more days on a boat.