Looks like he would qualify next year for the grade 4-6 Duke TIP programs, which would give access to summer programming. Robinson Center has summer programming starting at students leaving 5th grade, and Saturday programs for K-8, with optional concurrent parent classes. He will meet criteria for the summer programs, and there are no criteria for the Saturday programs. Also, there are multiple options, from supplement to full-time school/early college track, for students beginning in 8th grade, with entry points to full-time at 8th and 10th. Where you live in the region, these might be worth investigating:
https://robinsoncenter.uw.edu/
