Unless the parents are experienced backpackers, I would suggest leaving them at home. They generally "do more harm than good", so to speak.

Take qualified supervision and spend the time with the boys in small groups explaining what you are doing. 2-3 adults or older experienced Scouts (Troop Guides) would be good.

Depending on the numbers, you will need at least one other adult and preferably two.

Just my experience.

Oh, and be sure and try out the freezer bag (FB) cooking ahead of time. You can actually do this as one of your activities at a meeting in a controlled environment (ie kitchen).
You will also benefit if you make some bag cozies (see Sarbar's site to understand). You can make them out of Reflexics (sp?) or from windshield shades. You can get the Reflexics at Lowe's or Home Depot.