No problem! Hopefully you and Clarence will be able to work something out.
In the event you are unable to use Clarence's extra permit it is very likely that you will be able to get a "walk up" permit the day prior to your planned hike. People often wait until the final day prior to cancelling, or do not show up to pick up their permits. Also, it is common that groups "shrink", and at the time of permit pickup they drop the number of hikers, which frees up permits for others. Simply go to the ranger station the day prior to your hike and check for available permits. Being early helps, since I think that established your position in the Que. There are nearly always permits left over/unused. Your date is a popular one, so being early might be important.
Good luck,
John
