It's naughty o buyers to ask After they have paid to delay posting, as you may know this could land you with an undeserved late delivery mark on your account.
Best way forward is to explain the above and to avoid that defect you may need to cancel the order, and then relist when the buyer is available to receive the item.
Hopefully they'll understand and agree then you can cancel the order citing Buyer agrees to cancel. If they don't then cancel citing Problem with Buyer's Address. Not strictly accurate but neither option delivers any defects for your account, and refunds the buyer fully.
@maxmori
