You do need to split the PNR, you can call in. Some agents will remove the row 5 seat selection, if applicable, from your companion right away, others won't bother

You will get upgraded at ~T-48 as usual, depending on space

Your companion will get upgraded at the gate at ~T-1. I believe your companion is actually ahead of anyone with their own silver status, who now also get gate upgraded (along with everyone on promo fares) - not 100% sure on this

If you do not split the PNR, then you would likely get upgraded at about T-1.5, and your companion would be eligible again at the gate at ~T-1