I am in BC but my company's UAV insurance provider's Canadian office is in Toronto. The provider is Catlin Canada Inc. and the policy named "Remotely Piloted Aircraft System Insurance" is underwritten by Lloyds. I would recommend you shop for insurance using a broker because I don't think a company like Lloyds deals directly with the general public.
Transport Canada requires minimum $100,000 liability coverage. I carry $1 million because that's what my industrial clients require. The liability premium is about $1000 per year. I also have hull insurance and that premium is approximately 10% of the amount insured.
Catlin Canada Inc.'s address is First Canadian Place, 100 King Street West, Suite 3020, Toronto, ON M5X 1C9. I don't have a phone number for them.
Another provider who quoted me is Kiln Group Aviation Division (don't have contact info) and Avro Insurance Managers:
www.avroins.com based in Vancouver. Their quotes were all within a few hundred dollars of each other.