Darben,
I'm honestly not sure just how early Redcaps do come on duty at NYP, but I do know that they are there by 5:00 AM as they are available to help board the Carolinian & the Cardinal. However, at that early hour there are usually only 1 or 2 available. So you could be waiting for a bit until one can get to you.
Also, I'm not sure if it is still ongoing, but there was some contruction that was interferring with the normal elevator used by Amtrak. Therefore Amtrak was using the NJT elevator on the corner of 7th Avenue & 31st Street. instead of the one on the small now closed street running between 31st & 33rd streets. This makes it even more of a burden on the Redcaps as they have to go much further to get people to/from the street if they cannot use the escalators. Don't know if this applies to your situation or not.