Gatekeeper, look at the numbers, to help you decide.
The pension levy was 0.6% (0.75% this year) so work on a possible levy on bank deposits of 1%.
Interest rates here, low as they are, are still higher than you can get most places. Work out what after-tax interest you would get in the Canadian (for example) bank, and compare that with after-Dirt and post (estimated) levy deposit income here.
If the overseas option still seems more rewarding, then you still have to imagine what currency exchange rate changes there could be. How much of a drop before your foreign currency option looks the worse?
Yes, it's all supposition, but instead of floundering, you have put some numbers down and feel more confident in whichever approach you choose.