The traditional response is "Gey few, and they're a' deid".
I've only ever to my knowledge (left Scotland as a teenager) seen this in print.
Where does the emphasis go in the second part? i.e.
And THEY'RE a' deid, OR
And they're A' deid? Or even
And they're a' DEID?
...mmm....well speaking only as an old sassenach maybe I'm notactually qualified to comment.....I love old Frazer and his "we're aaaaa' dooooomed!" just came to mind and the heavily stressed a' sounded just right....