What is your site built in? Do not make business decisions based around a shipping widget!! They are easily replaceable - get a new one.

When shipping internationally you need to think about 3 things - tracking, shipping fees and duties.

A. No one wants COD charges at door. Have to figure out how to build them into cost

B. Never send USPS - its sucks internationally and takes double time they claim, especially to Canada. The lack of tracking on any package does neither you nor the customer any good

C. Flat fee including duties is always better no one will order a $17 dollar item if it cost $25 to ship! Need to look at how you can set minimum order size to make the math work for you and the logic work for buyers