Originally Posted by
Hagbard Viking
Here's an example with a bit more than 69,000 miles:
lhr-dxb-lhr-lax-sju-dfw-anc-dfw-mia-scl-ccs-scl-gig-scl-dfw-nrt-sin-nrt-sin-nrt-lhr
It shouldn't be too difficult to optimise it a bit further, including finding a cheaper starting point than LHR.
Substituting PTY or even YVR for ANC in the above itinerary still makes it exceed the magical 66,667 miles and should work year-round...