Sorry, I have only just seen your post/question, because I no longer take a strong active interest in this site.
With regard to the question, your wife is correct in her insistance. There was a branch of Halifax Building Society quite close to Wigan Infirmary.
I am not 100% sure of the date, due to the decades which have passed and also that the branch was only open for a short time: I think, it was less than one year. I would give a guess at it being open around the mid 1980s.
But! I am 100% sure of where the branch of Halifax Building Society was:
- A branch of Halifax Building Society was located at the top of Clifton Crescent on the left side (on the corner) as you looked down the crescent from Wigan Lane. I believe, the address is 'Wigan Lane' as the front of the house and the front door face Wigan Lane, with the side being on Clifton Crescent. The building, which originally was a family home (a large detached-house with surrounding gardens), still stands; I think it is back to being a family home, but I haven't taken a close look for quite a time.
I hope this helps.