Weather permitting-Shannon/Dublin to/from Bangor/Gander should work, based on the LR60's 5+30 range. I doubt ELLX to Bangor non-stop would work, but Gander-ELLX should work. On Newfoundland, there is Gander, St John's and Stephenville, further down Halifax and St. John, NB before you get to Bangor. All of these destinations have good services, ILS approaches, and good overnight facilities. OK, maybe not Stephenville.
I wouldn't put huge trust on the marketing charts-remember they use LRC cruise, 85% winds, nearby alternates (good weather in the NAM?) and 30 minutes fuel remaining at the alternate.
GF