Daryl,
If you select to complete your circumnavigation at the end of September by descending the MR, follow this Message Board to see how conditions are changing up there. Yesterday (September 2 at 10 AM) peering down the cute descending from the summit plateau to the Notch (the "final 400") on the MR, it was not obvious from above that the bottom segment was in fact clutttered with ice. In unusual form, yesterday the "easy traverse" was actually safe. Earlier this summer this traverse appeared to be an invitation to a sudden death (ironically, depositing one back at the small lakes far below which had been earlier passed on the circumnavigation route).
Of course, the MT always remains an option. However, at the end of September its condition too might not be optimal. For sure, though, there will be another full moon then.
Jim
PS: Verify that the permit reservations you currently hold will enable you to do what you finally plan. If you are not doing the circumnavigation in a day, you might actually need permits for the North Fork of Lone Pine Creek.