Firstly, think about travel from Watford to Cheam. Are you planning to relocate?
Your DD might get place from waiting list, if not on the allocation day. It depends on the preferences of other candidates too.

But looking at your other posts, your DD has taken tests all over London and elsewhere. You need to put some focus. Is travel to Colchester easy from North London?

Thanks for your reply Tiffinboys,
We will relocate to either Cheam or Colchester if we are lucky enough to get a place in one of them . I will put Nonsuch above Colchester in the CAF if there is a chance in Nonsuch.

Regards
dsme

So...

Say you get ColCHS on March 1st. Will your strategy be to say, 'That's fine' and concentrate on finding somewhere to live in or near to Colchester? Or will you hang on for a while, in case Nonsuch or whichever school comes up on the waiting list? Then, hang on a bit longer, 'you never know'? Etc. Will your DD in reality be starting year 7 commuting from Watford to Colchester?

_________________
Outside of a dog, a book is a man's best friend. Inside of a dog it's too dark to read.Groucho Marx

Surely there must be other factors, apart from the school, that you must consider before relocating your whole family to a new area?

-How easy is it for you and/or your other half to commute to work from Cheam and Colchester?
-Have you compared house prices? You can buy a big detached house in Colchester for 450k, whereas it will cost you double that in Cheam.
-How well do you know both areas and which one do you and your family actually like more?

It is important to remember that the school you get on offer day is, in most cases, the school your child will be going to every day about six months later. If you're offered a school that you can't reach without moving house, you will find that you're under huge pressure to move in time for starting in September, dealing with primary school places as well (including for any younger DC). It's quite a risky and stressful situation to put yourself and your family in.