Here's a possibility...
Yes, it will require two non-hiking
drivers and a spare set of keys, but IMO it appears the simplest solution.
- Cars #1 & #2, along with the hikers drive up to Tule TH
- Drop off the hikers, one of whom must have spare keys for car #1.
- Drive cars #1 & #2 to the Reavis TH
- Leave car #1 at the TH
- Both drivers drive back to Phoenix in car #2
- Hikers show up at Reavis with keys for car #1, which has been waiting patiently for the hikers to arrive and reclaim it.
P.S. Depending on WHEN you wish to accomplish this and IF driver #2 is willing to hike a short distance out-and-back with me, or wait while I do so, I just may be available to be the extra driver.
PM me with details of date/time if your driver #2 is open to it.