Like many of the parents here, over the years you may find that nothing is sufficient...
- as most gifted programs teach one year ahead. Period.
- as highly gifted and profoundly gifted kids can have strong internal motivation to learn... some describe it as:
  • driven
  • compelled
  • unquenchable thirst for knowledge
  • intellectual curiosity
  • highly observant
  • etc
I would strongly agree to place your child among academic/intellectual peers... or the nearest which can be found. As you mentioned, a school more familiar with gifted pupils may also be more open to advocacy.

In order to develop well, gifted kids need what ALL kids need:
1) Appropriate academic challenge,
2) Intellectual peers.
However the appropriate academic challenge, and intellectual peers, do not match those of the typical chronological age cohort.