For those who are still looking for composition workshops to attend this summer, below are some still accepting applications:
Oberlin Young Composers Workshop (Jun 24 - Jul 1); deadline: May 1
https://www.oberlin.edu/summer-programs/composition-workshop
Oberlin Sonic Arts Workshop (Jun 17 - 23); deadline: May 1
https://www.oberlin.edu/summer-programs/sonic-arts-workshop
University of North Carolina School of the Arts Summer Composition/Music Technology (June 17 – July 7); deadline: May 1
http://www.uncsa.edu/summer/music-summer-intensives/composition-music-technology/index.aspx
Illinois Wesleyan summer composition (Jun 17-23) (deadline: May 25)
https://www.iwu.edu/music/k12/summer-music-composition-institute.html
Maybe others can add to the list?