To update the thread, the upgrade bid price dropped to $960 USD - circa 48 hours before departure. I ended up bidding this amount but was sadly unsuccessful.

I think this may in part be due to the fact that the earlier flight to mine (VS20) was cancelled forcing more passengers onto VS42. Still had access to the Clubhouse at SFO courtesy of AMEX (a pleasant surprise), so had some nice food and a shower and then had a decent experience in Premium Economy.