Going across the pond can be a bit of a task. However a popular route for aircraft which have limited range is via Iceland, Greenland and Canada. You need to be able to fly 700nm for each hop on the longer route with one airport on Greenland or 450nm with 2 stops and also calculate the point of no return (halfway point +/- wind +/- weather).
The 7 airports you need to know about are as follows. You arrive or depart from Iceland and Canada on a route of your choice. AVGAS and Jetfuel available at all these airports. Iceland and Greenland are not a problem for visas usually. Canada has CANPASS call latest 2 hours before. USA is more difficult. If you enter from Canada you must have a visa issued before you arrive. If you are inside USA and leave via Canada you can use eAPIS and fill out the details online.
Hint: When you file the route, you have to take note of the following. The route includes waypoints that are not on your nav (Garmin/Avidyne) but are coordinates. On a Garmin for example enter 57N and ENT, then it asks you to create new waypoint, here you select N57 00 W 55 00. Every waypoint the controller will expect you to transmit a full position report so be ready to say this to Gander Radio.
Example ” G-ABCD checked LOACH 1012, maintaining FL150, estimate 57N55W 1357 next 59N50W “
A good idea is to put your avionics flight plan to show ETA and show the times instead of distance.