Contributory Widow's Pension is payable outside the state (once you meet the other criteria - not remarried, not living with anyone).
Here's some information from the Widow/er's Pension Guidelines on Welfare.ie
A Widow/er's Contributory Pension is payable outside the State. A person should notify the Department of the date of departure and his/her new address, if the absence is for more than a few weeks duration. If paid by payable order book, the book should be returned to the Department and arrangements will be made to re-issue payment by Electronic Fund Transfer directly to the persons bank account in the State or outside the State, as requested.