Note that it doesn't take a huge amount of pre-planning for a ship location. He has posted the ST cycling route locations, so conversation can be something like, "Are you still going by way of Silver City/Las Cruces/Sierra Blanca? How far away are you now and how long are you expecting it might take?" and then "Ok, if you need, I how about I send you X to the post office at Y?" After that, send with his name to General Delivery with the town and zip code and give yourselves and extra day or two so he doesn't get stuck waiting for something to arrive.
Yes it works quite well, but not always flawlessly. Too often we passed through towns before or after the post office hours or on a Sunday. Unless we wanted to hang around, the solution was to go to any post office and tell them what post office you have a package at and where you want it forwarded to, but this obviously delays deliveries. At least they do not charge for the forwarding.
Given Ryan's tight schedule he can't afford much waiting around for a post office to open.