About 1987/88
. . . when the UK did almost run out of QRA F-4s (I think I remember reading the latter on PPRuNe).
SNAF sent 4 pairs of Bear Foxtrot south through the Faroes Gap at 30 minute intervals, they then transitted via the Denmark Strait back north. As you surmised, that dragged QRA to the max, UK and Iceland with maxi tanker support
IIRC a home bound T* from Akrotiri, with pax, was also used for tanker - tanker top up.
Now if things had got really busy . . . .