On my way to the office this morning, I got a call from the bank branch near my office telling me my foreign currency transaction had arrived. (That's not bad; it was only processed on Friday.) So I stopped by on my way to the office and collected my JPY120,000, which was mostly 5K notes but also had some 2K and 1K notes, so we should be okay.
Based on the exchange rate, the rule of thumb conversion of 100:1 (drop last two zeros to get dollars) seems like it should work most of the time.
Edit, 21 Aug 12:35: Corrected order-of-magnitude error on the bill denominations.