Just general knowledge of how UPS operates after 15 years with the company. We tend not to pile stuff up in a corner because the next day there will be even more piling up. We work until the job is done unless there's some factor that precludes getting everything out that day, like weather, etc.
For example, I typically work a 4 hour shift, but I have had days where I've worked 13 hours during the holidays because we had to get everything out. Obviously stuff can go wrong. Your plane could crash so I can't say anything with 100% certainty, but if you're picturing a UPS building as an empty warehouse with room to stack giant palettes of iPhones, you're not picturing it correctly. Watch as many people get departure scans the next 2 hours and hope you're one of them. Like I said, I'm right there with you. Frustrating that my phone is one of the ones with no activity since last night, but I know that they're operating on all cylinders there right now, because as soon as they finish this batch there's hundreds of more batches behind it.