I appreciate all of the feedback. Late december is definately easier to go (will have holidays anyways between Dec 22 to Jan 1), in which case i wanted to combine the wave with Havasu. I already booked Sept 23 to Oct 9 for Yellowstone and the Tetons, so i've got very limited holiday days left, so going during the xmas break would make it work from a work perspective.
i may have a conferance in vegas from Nov 26-29, which is why we tried for the dec 1 date as well. If the conferance is a go, i'll definately do the wave on Dec 1.
We've got until Sept 15 to finalize our permits, so we may just book both days anyways, coz, i won't know about my conferance until the second week of October.