You’ve probably already found these, but in case you haven’t, these are possibilities.
Wentworth’s ImpactLab | Wentworth which would allow a primary major (STEM) and a humanities-focused for a minor (like psychology).
Summer Pre-College Residential Programs at UMass Amherst : University Without Walls, particularly Summer Engineering Institute : University Without Walls
Wake Forest’s summer immerion programs, https://immersion.summer.wfu.edu/, particularly the Business Institute, Engineering Institute, or the Finance and Investing Institute.
https://universitycollege.tufts.edu/high-school/engineering-programs-summer