I don't have much time, but I did want to comment that HG+ kids often do well the first year of a multi-age classroom, since it gives them a higher ceiling and older kids to befriend. That part sounds like it could be good in either of the two classrooms.
The downside is that they often need something else in later years. Being the oldest child in a multi-age classroom can be a real problem for an HG+ child.
I don't think that's a reason to avoid a multi-age classroom for that first year. One year at a time! Definitely!
If one of the schools looks like a good solution, I say do it! But it does mean that you can expect this solution to have a limited shelf life, perhaps even more definite in its limitation than many educational solutions.
FWIW...
