yes, for this discussion a small number was five at a particular date, and likely to be less by now.
I got the information from Islington Admissions, but not in terms of individuals, just postcodes (of course!) so I looked at a postcode map and took the general area of the Whitehall Park conservation area which has a legally exactly specified boundary, and the borders areas around it so erring in the direction of overstating rather than understating especially as the numbers are so low. And of course post code area boundaries are odd shapes and not particularly "granular" I could have argued, for example, that there were only three as the other two too far away, but why bother? And anyway you dont know whether someone is in the middle or the edge of a postcode.
As I got the information from Islington I do not have the same information from Haringey, so I cant really say much about north of Hornsey Lane, except north of Clairmont you are moving into the admission area for Highgate Primary, and that this year the south end of Clairmont was in the radius for Rokesely School, as well as just on the boundary for the first wave of offers from Ashmount and Coleridge, so there may be offers form the waiting list.
(I got some individual case information from Mumsnet -the person at the north end of Clairmont who preferred Highgate Primary to Ashmount as they thought Ashmount too far, the person in Whitehall Park to the west of the old site, who missed out on the first round for Ashmount but now offered off waiting list -any more contributions of this sort welcome!)
I will post later about what might happen next year.