School for small children (São Paulo)

Hi, my husband had an opportunity to apply for a job in Sao Paolo.
We have two small children, aged 5 and 3, both Dutch speaking. Does anyone have any experience in moving with children of that age, who don't speak the language? Our eldest is due to start primary school next term, so it's quite an important year for him.

Any thoughts or experiences are welcome!
Thanks, Chantal