Try your local Commissionaires office...or good 'Ol Google.
As a U.S. citizen, you might consider using one of the FBI's approved Channelers, since CIC is once again accepting those:
https://www.fbi.gov/services/cjis/identity-history-summary-checks/list-of-fbi-approved-channelers-for-departmental-order-submissions
You won't find any of the Channelers in Canada, but you can mail your fingerprint card to them and they will process your request. I believe they are required to send the letter to a U.S. address, but it can be to family/friends, who will then forward it to you in Canada.
The FBI IHSR letter takes ~ 12 weeks if you go directly to the FBI (cost is $18), versus a week or two with a Channeler (cost is probably ~ $40-$50).