I’ve heard of overnight events in which kids to college aged people spend the night at the masjid (but there is segregation!) or there are Islamic conference/camping trips. The difference is that with the camping trips, the guys and girls are not under one roof. They’ll be in separate areas and even eat separately. And sometimes because an event is sponsored by the masjid or takes place at the masjid, people will think twice before intermingling.
Same here.