Your point is well taken. When I wrote my comments I was thinking of something along the lines of EGLL to KSFO/KLAX and maybe even KSEA westbound.
Wonder how many times SAS made the Tokyo trip non-stop back in those days as opposed to a pre planned technical stop in Anchorage?
As I recall TWA avoided the higher latitudes (Doppler/Loran only), so as to eliminate the need for grid navigation where as Pan Am who operated with Nav/2nd Officers did operate at the higher latitudes. Don't bet your last dollar on my memory.