turning off instant booking for dates further than a year out

[Cory0]

I had a guest instant book for dates over a year away, where the prices should be at high season.  I had not updated my calendar for that far ahead of time yet.  Is there a way to turn off the instant booking for dates further than a year out?  As they did not want to pay the higher fee, they have asked if I would kindly cancel the reservation.  There are penalties involved towards me.  😞  Any suggestions?