I spent a lot of time researching Summer film intensives for S19, including the ones you mentioned. Cost was the biggest factor for us, so we looked for summer film programs with scholarships. NYU has a single (competitive) full scholarship available for their summer filmmaking program.
http://tisch.nyu.edu/special-programs/high-school-programs/filmmakers-workshop
I don’t know if the app is still open, but Anthony Quinn Foundation provides scholarships specifically for summer intensives.