11 months because my partner needs to be "booked" even earlier than that when possible, and in return for that tme-off commitment, I can't say, "psych, I didn't really buy the tickets! And now they're not available for the dates you turned down work...".

(1st ticket purchase less than 4 months is a legitimate non-starter because of all the clients who would have to be cancelled on, and there definitely wouldn't be 3 open weeks. 4-11 months means domestic strife because scattered bookings mean there are no uninterrupted 3 week periods, fights about cancelling on people.)

Nevertheless, flexibility is desireable because 11 months is, indeed, insanely early to book plane tickets - you are right there! :-)

Thank you all for your advice... sounds like business with $200 as the change fee will be the right choice for us!