To provide scaffolding for the students, I worked with the teachers to help them create a template Google Presentation that was shared with each group. Teachers added in the titles and some subtopics to each of the slides, in order to give the students some structure. Then the teacher shared it with one member from each group as "View only". This group member then opened it within their "Shared with me" in Google Drive and clicked File > Make a copy in order to personalize the template for their group's assigned country.
Once this copy was shared with the other members in their group, all students could work simultaneously on their presentation, most finishing within 30 minutes. The kids got so excited to see that multiple people could be working on the same document at one time. They enjoyed adding images and video to support their writing, and they look forward to sharing it with their classmates next week.