Legal Question in Real Estate Law in New York

Easy answer: Hire a new lawyer.

What your lawyer should have done was send a time of the essence letter to the seller's executor, attorney, and, if known, heirs. The letter should explain why (you're losing your mortgage commitment due to seller's decease and executor's failure to convey the property). If there is a probate problem (e.g., a will contest) it will take much more than two months to unravel the problem.

After sending the time of the essence letter (assuming, of course, that title is clean other than the death of the seller) you appear at the bank on the appointed day. If they do not show up with the deed, you send notice to the executor etc. advising that due to the breach of contract, you have elected to terminate the contract. You then file a lawsuit to enforce your buyer's lien. Play this one correctly and you get the house in exchange for the downpayment...which is why if they have any sense they would offer to pay back the downpayment plus closing costs incurred to date.

This way, you don't lose the downpayment. And mirabilis dictu, the odds are that they will get their act together. Especially once the surrogate finds out that the sale is going to crater. Properties in Nassau don't sell for real value these days. The surroggate will most likely find a solution that gets the title to close before your lock evaporates.