I have been in 'discussion' on this very issue with a large assortment of ...
...people in authority.
Headmaster, Division Head, Teacher in Charge, School Nurse, my Doctor, etc., etc.
The clear consensus is that exposure doesn't equal contagion. If I feel good going into the trip, I will forge ahead -with the approval of all in control of the trip.
I asked that same question at the end of last week, when it became clear the family was going down hard. The option of cancelling the whole trip is still on the table, and will be made in the best interest of the kids, closer to departure.
I am feeling good that all points have been, and will be, considered.
Michael