And opening Heathrow H24 for passengers would mean persuading British Rail, the underground and bus companies to start night operations. It's not going to happen.
Never say never. In aviation needs must, and there are MANY examples, where changes were made to satisfy an increasing population and more and more transport - including aviation.
Even a third runway
will happen if it must. Politicians have a nasty habit of saying 'it will not happen' but after they have been rejected by the voters (or reshuffled or sacked) it
does happen. You might even suggest that Justine Greening, a fierce opponent of a third runway, has been moved to where she no longer has a say, which allows for a more conciliatory Transport Secretary to take a forward step in this case.
LHR is such a case and IMHO I think a third runway will be built. When is another matter!
The mad Mayor's idea of another airport is an absurd option given the huge expansion at SND, with probably more to come, would create massive ATC headaches and cost far too much. Anyway, Stobarts are growing at a huge rate and will be seeking more return on their investment. They will not sit still and ignore such growth around them. Unlike Boris they are not fools.
Watch this space, as they say...but watch the flak too, it will be immense.