Least-worst options usually involve part-time or full time acceleration. No one really wants their child to be sitting next to older kids all day - but at least the child is sitting next to kids of some kind all day.
Challenge in afterschool and in summer works well for some kids.
I think the next best thing to a crystal ball is to observe who the child reacts to novel learning situation, and to learning situations where some work is required. If the child only wants to play if they are sure to win - that tells you a lot without a crystal ball!
Smiles,
Grinity
