How about eight divisions on four fields

[Greg Marra]

Originally Posted by Lil' Lavery

Regardless of whether or not you do this as two "sub-divisions" or just add another round of elimination matches (and 8 more alliances), you're adding eight more sets of 2-3 matches that need to be played per field. Minimally that's 1.6 hours of more playtime, and it could potentially add as much as 3.3 hours to the schedule.
Simply put, no way.

Put another way, Eighthfinals represent more matches than Quarterfinals, Semifinals, and Finals put together.

That being said, I believe GTR used to do Eighthfinals back when they had two fields. They could run these in parallel, so they were able to fit more matches faster.