We faced that issue 18 months ago, the kids were 2.5 and 4.5 yrs then. They went to a "cosy" farm type school in the southern hemisphere on 7 acres of land with horses, chickens, fish and although it was cosy, they did have 200 students. It was well run and efficient.
We sent them to the Chinese
International School mainly for the language component and the older child having to face primary school. The transition was easier than I thought, the kids liked being in school uniform. The school was actually way smaller at about 120 kids. They picked up the language and have settled well.
I think kids are very adaptable.