I ordered a new 85 in July 2014. Deposit on my Visa. Got a call from the DS on November 3 2014 that my car had arrived and they could deliver on the 5th or 6th. I had to delay because my wife had been told she might be terminally ill, and we would know for sure on Nov 5. I was told that Tesla would refund my deposit if diagnosis was confirmed. Sadly, it was. On the 5th or 6th I called the DS and told him my wife's illness had been confirmed. They never asked for any proof or anything like that. What a stand-up company! It took a few months, but Tesla refunded my entire deposit less $750 for the wall charger, which I had already installed (otherwise they would have taken it back).
So yes, in exigent circumstances, Tesla will quite likely refund your deposit even up to the time the car arrives in the showroom, as mine had. I hope no one else ever has to find this out like I did.