If your customer agrees to add escrow, you would not be prevented from adding the flood escrow prior to January 2016.
If the borrower does not wish to escrow at this time, then I do believe you would need to deliver the opt-in escrow notice between January 1st 2016 and June 30, 2016 in order to comply with the timing requirements.
_________________________
"It's time for the Jedi to end."
Luke Skywalker