We send boxes and/or plastic drums all the time. They usually take about 6 weeks to get to SD from NY. Once they arrive, they have to clear customs, which takes varying amounts of time. Don't panic yet. In March our drum was in customs for over a week, and my husband was talking to himself by the time we got it.
We're going for a month in late December - so we'll ship our drum in early October, the latest, so it's there for sure by the time we get there. We send all the heavy stuff that way.