We first need to answer a few questions
What kind of insurance do you need, you say travel but do you mean:
Baggage & Delay Insurance
Travel Medical
Or Travel Accident
or just plain old Health insurance while in Canada?
Are you legally working in Canada on a work permit? Or are on USIT u35 working holiday? Are you travelling or working? What is your status in Canada.
If you have no status in Canada, no permit, no residency card or otherwise, for certain matters you are considered still a permanent resident in Ireland. Do you maintain an address in Ireland?
Most Irish companies will offer a package for those working abroad however premiums for North American coverage range in the thousands from 2000 euro and up.
Will you be leaving Canada or are planning to stay? Many insurance companies in Canada can offer basic travel medical insurance coverage for VISITORS to Canada from around CAN$1550 a year, they charge it per 30 day blocks much like standard 'all in' travel insurance. This is obviously much cheaper than buying coverage in Ireland.
The catches are that these policies do not cover everything and the cost of your policy is often based on the max sum insured starting at $10K upto $150K. There often restrictions based on how long you've been in Canada already aswell.
http://www.healthquotes.ca/Travel/Visitors/?gclid=CNrQq8zFzIgCFQpwYAodADLBDg
If you are in Canada on a work permit (not working holiday visa) you may be eligible for your provinces Medicare depending what province