Form teams of 7 at the earliest opportunity
The expedition section doesn’t get real for participants until they are in their teams. Remember the main motivation for them isn’t to spend time admiring the countryside, it’s to go away with their mates. So it’s only once they are in teams that they get excited about the programme and are motivated to learn and plan.
Teams of 7 are best because:
You can supervise more participants more easily
You don’t have to stagger lots of smaller teams if route choices are constrained.
If people drop out, you’ve still got a viable team.
It’s easier to slot less popular kids into larger teams.
We like to form teams at the first meeting, having them write names on A4 sheets and getting “usual suspects” team photos. That’s the moment their expedition journey begins