Marc, waiting 12 weeks for the second dose of AZ is actually a made up story by the Government.
This is said because their roll out is so slow and that they do not have sufficient dosage for all to do a quick turnover.
We live on the same property of a wife and partner who have both had the second dose four weeks apart and was told that even two weeks is OK.
She has now flown to the States and her partner will follow next week.
Leon