The Hollywood star will move to the UK with their son Joe, seven, and Winslet's daughter Mia, ten, when Sam Mendes directs Daniel Craig in the latest Bond movie.
The 007 adventure is likely to be filmed some time towards the end of next year, with the production based at Pinewood film studios.
Kate told British newspaper the Daily Mail: 'Sam is doing the next Bond film, all being well, and we'll all be in England if that happens. It is such a massive commitment for him and it's not fair for him to commute backwards and forwards to New York from London. It would be impossible. The children will be there with me.'
The pair seperated last year but they appear to be on good terms, because they still like each other and because of their children.
Despite saying she won't be playing a role in the Bond film, the 35-year-old didn't rule out working with Sam, 45, again.
She added: 'I can see us working together again - that's the way it is.
'We're really good friends and have very good respect for each other. I can see it, but you'd have to ask Sam what he thinks.'