« Reply #33 on: Thursday 19 June 25 12:30 BST (UK) »
If they forgot to tell the vicar, then I expect he would carry on reading the banns as originally scheduled.
Ancestors of mine had banns read in Norfolk (all three) but did not marry there. Then almost immediately had the set of three read in Essex. I had wondered if one was from Norfolk and one from Essex and the banns reading was out of sync in their home parishes. But in both sets they were both of the parish. He was in the army and although I haven't got his service record the regiment did move between the two places at around the right time. They did marry in Essex after the 3rd reading of second set. I wouldn't be surprised if they had already left Norfolk by the time the readings of the 1st set were finished.
This was very late 18th century, not much earlier than your couple
Berks / Oxon: Eltham, Annetts, Wiltshire (surname not county), Hawkins, Pembroke, Partridge
Dorset / Hants: Derham, Stride, Purkiss, Sibley
Yorkshire: Pottage, Carr, Blackburn, Depledge
Sussex: Goodyer, Christopher, Trevatt
Lanark: Scott (soldier went to Jersey CI)
Jersey: Fowler, Huelin, Scott