I contacted the hotel and asked if it was safe to buy non-refundable airfare at this point, in anticipation of a Mar 1 open.
They responded:
[W]e do indeed hope to stay on schedule with that opening date. However, the resort is still in its construction phase and is subject like any project to unforeseen delays at any time. We hope that there are none, but this is worth bearing in mind as our new resort gets ready to open.
How can they require a 90 day cancellation period, but at the same time cannot even certainly say they'll be open?