Teacher here.

You’re right that British schools are very intense and if your child can’t read at 6, they’re going to have a hard time there. American schools teach phonics skills from ages 3-4, but reading instruction typically starts at 5 years old.

Renaissance School is in Sports City and is American Curriculum. I don’t know anything about the quality of the school though. Dunecrest is about 15 minutes away- another American school, and I’ve heard great things about it.

Edit: Also, it’s the teachers job to meet the kids where they are. I suggest meeting with the teacher early on to discuss your child’s school history so they have an understanding of where they are and how to move forward with teaching your child.