Why not just increase the patrol members to 8 per patrol? The syllabus allows for 6-8 youth per patrol. With 8 patrols that would take you up to 64 participants. The minimum size of a Troop for NYLT is 4 patrols, but I think it is much better to have the interaction of 6-8 patrols than it is with 4-5 patrols.
I do agree with having 10 TG's though, seems one or two always drop out at the last minute or aren't quite up to speed yet by course time.