Dude! You can stop in at any USPS Post Office and mail it. It would take just a few minutes! There is one in every town, so you will pass by dozens on your way south.
I meant if there would be enough time between mailing it and when we need to pick it up at the supply post. Sounds like they suggest mailing it 2 weeks before you intend to pick it up. If we resupplied early on in the trip we wouldn't have a chance to mail it out 2 weeks ahead of time.
