One of the purposes of a Coronation is to show off the new King or Queen to the public, with soldiers on parade and marching bands etc.
I suppose it has to be a religious location (and a Protestant one at that!) given all the blessings and prayers I watched yesterday.
The various
Royal Peculiars aka royal churches are very small. Good for a very stripped down low cost event but not on the scale of yesterday. St Georges Chapel at Windsor followed by a drive to Buckingham Palace for the balcony and parades is most likely.
York Minster has the historical connections and internal capacity but it's in a very cramped city environment.
Salisbury Cathedral is surrounded by large fields so is easily secured and has plenty of space for the new monarch to inspect their troops. There is also the Magna Carta to remind any newly crowned heads that the law applies to them. But no Royal Palace nearby to travel to.
How about in Edinburgh at St Giles (where Her Majesty laid in rest), a nice long parade via Princes Street and then up to the castle for an afternoon of Edinburgh Military Tattoo-like festivities. The King can then head off to Holyrood for the night.