Flights to Canada can be pretty cheap too. Less than the cost of one month so if you flew out every 90 days you’d still come out ahead. Practically not enough people will do this of course. Would be great for people in the border towns though.
Also, let's be real, anyone in the northeast could be there in a few hours driving. New York City is about 7 hours away from Ottawa, for example.
I’ve ended up at the border crossing from Niagara Falls to Buffalo by accident before. I was glad when they let me make a U-turn.