Elon posted on Twitter that if your car isn't delivered by the end of the year you can get a refund for your deposit.
I believe that is for new orders as Tesla is making a year end push.
https://electrek.co/2018/12/11/tesla-end-of-the-year-push-referral-program-cancellation-waitlist/
I'm still hopeful that Tesla will make a price adjustment if they miss their guaranteed delivery for those ordering before Nov 30. Of course, it would be preferable that we actually get our cars by year end and not need to find out what our recourse would be.