Thank you everyone - so much to think about!

I was told by a mother who has older kids at the current school that based on past experiences ds could be moved up to the next class as early as next term to make room for new kids ( they start on their 5th bday here) I guess that would give us 6 months to see how he goes in the bigger class. This btw is how they handled dd’s skip - 6 months in each class.