I’ve just returned from San Diego to London Heathrow, direct flight by BA.
My outward journey was tracked by a friend using Flightaware and FlightRadar24 and both appear to vary considerably.
Flightaware seems more South, out over N Ireland, missing Iceland, South of Greenland then in over Canada and US whereas Flighradar24 suggests Scotland, passing over Southern Iceland and Greenland then Canada and US.