Still not sure what you are allowed to do, but if I had to send one of my trijets across the pond today, I would probably fly this: CYQX..5050N..5140N..5230N..5220N..LIMRI, this is the optimized route for today (not taking into account the tracks, you need to fly below/above or between the levels in use).. .As you are flying a twin, I would still suggest to comply with a 120 rules for your enroute alternates (I always use BGBW/BIKF and EINN).. .So the route above might be a little bit south to comply.. .As fcit told you above, the blue spruce route might be a safe option, I've done it a couple of time when our small twins need to go home for maintenance, but with a brand new 738, I am sure you can fly a more direct route. But again, it's all question of what you are allowed to do by your company/country regulations and aircraft equipment.