You could use localbitcoins to offload one coin at a time on an as-needed basis. That'd be pretty sweet, and the IRS won't be able to know anything strange is happening if you avoid depositing your USD into a bank. But paying rent in all-cash is rather sketchy. I wonder if drug dealers deal with similar problems.
I don't know how plausible this is, but the localbitcoins route might also open you up to being kidnapped. You'd need some pretty decent opsec to avoid revealing that you have a massive amount of BTC you're trying to offload.