Looking to book SQ317 LHR-SIN preferably for Jan 12, but no aisle seats seem to be available when using 'seat selection' on the SQ site. Ideally, I want row G on the main deck, or the equivalent (F?) on the upper deck.

Is this because every seat has sold out, or is it because SQ are withholding certain blocks of seats until nearer the time?

I have emailed SQ but am yet to get a response.

How can I tell which SQ317 has an aisle seat left available (date is flexible, just need the right seat), without dummy booking each date?

If it makes any difference, I am KrisFlyer Elite Silver.