Thanks, those were interesting articles, but they really work against your argument.
For example, a propos the quoted remark that <<Peter Russell, Matthew Elliot, and many other distinguished men who sat on the Legislative Council of Upper Canada each owned dozens of slaves.>> your second linked article says that <<Resistance from the eleven slaveholders in the twenty-five member first Parliament of Upper Canada forced Simcoe to rethink his bill.>> Eleven slaveholders, the biggest of whom own "dozens of slaves" means that the smallest of whom own 24 or less; say that half own "dozens" (24 or more) and half own fewer than "dozens" (23 or less) and pick 23.5 as a representative figure for the number of slaves owned by each of the 11 slaveholders - - 258 slaves owned by the legislators?
We're not really talking about a hell of a lot of slaves. There just aren't any Ontario counties with anything near the black population of the rural counties of the Southern States. The anecdotal evidence is highly interesting, I admit, but in reality, there just isn't any real evidence of massive slave-holding in Ontario.