Theoretically based on the POR, you have 1 year to give the release, however, it really all depends on your broker, whether they will provide you the additional opportunity to tender your release beyond the "voting" deadline.
Also, you have to factor in the T+3 settlement time.
I took no chances, I sent mine in.
Bottom line: It all depends on your broker. Not all brokers are the same and have different procedures.
Sorry, i could not shed any more light on the subject.
imo