Originally Posted by
Palal
AFAIK, you don't need an appointment to get the CBP sticker after you update your passport information
That is the case at least at IAD.
If you have already received conditional clearance, you need to schedule the interview within 30 days. I'd do that, and then update your passport online once you've renewed. Get the sticker on your next trip to an airport with GE CBP office. Carry the old one with you that has the sticker until then if you need to flash it.
BTW, with only 6 months on your passport, you should renew now anyway, unless you have no international travel plans, because you generally should have 6 months of validity left.