Sounds like you're waiting for the top to get most of your loan. There's only down from there for 4ish years after.
Whatever you do, have enough collateral for a 80% drop plus consider that the fees and interest is always dropping your LTV and then be prepared to deposit that collateral as you start with 50% LTV which protects for up to <40% drop in price (I think).
Good news is I guess you don't need to worry too much about rehypothecation, so you just need to focus on your own risk management.