Using the Boeing BLT you should be able to go ISP to LGW non-stop on a good day with ETOPS reserves. If not a quick tech stop at YQX would do the trick. You might have to limit your pax to 110 during the summer but would be able to do a full load in the winter. It is not as far as you would think. Flight time comes to just over 6.0 hours with an averge 80 knot tailwind.