Many thanks to you all for the nuggets of wisdom.
Some of the best prep schools (tuition > 25K for 1st grade) we visited had snobbish responses. One school head said, "We have many kids doing better than 142. We have a K child who tested at 160. (Nothing about a differentiated approach)." Another head said, "IQ doesn't really mean success. You need all rounded education if you want to go to the ivies". Yet another said, "Our curriculum is structured very well (without individualization); that is the reason we have so many high achievers".
Their responses made me feel apologetic for my DS's abilities. Looks like this is going to be a long journey with many trials and errors!
