I am closing this form as I was shared a more efficient spreadsheet where you can form groups:
https://docs.google.com/spreadsheets/d/14TLTasofn7DKbM0QsMTBg_LMuPcj7xwHytyMGjptOUU/edit?pli=1#gid=858821924

To the people that registered until Monday 19th (included): I have sent calendar invites for the groups I was able to form and an email to the rest.