Interesting you raised that John.
I was thinking of exactly the same route.
One of the problems with flying long skinny routes tho is that current range/payload capabilities make anything ultra long haul marginal in terms of economics.
A change in aircraft form factor is probably needed.
A blended wing body, powered by geared turbofans = 30% increase in fuel efficiency. Makes a 787 seem like a gas guzzler.
Quite why the airframers are worried about passenger objections to not having a window beats me. Most long haul flights are conducted with pax watching IFE or sleeping.
And I'm sure the problems of pressurizing non-cylindrical fuselages could be overcome.
I'll be an old bloke by the time it happens, but I'm sure we'll see non-stop antipodean / north hemisphere city pairs by 2030 or so...