I have bid for BIZ class a few years back on Rouge
closer to the date maybe a month out
I just keep checking what seats were available then when they start to fill up make a bid
Make sure you do not overbid or you may as well just book now
We did get the upsell but no seats together this was from Florida so maybe Chile would be harder to get the upsell
Also watch the sales sometimes they offer a cheaper price for non refundable BIZ
We did R/T AMS & took the lie flat seats it was not cheap even for non refundable but well worth it to us old folks
YMMV