So just an update from me.
Was looking to book an upgrade from Economy to Business for CPH-BOS on Jan 13th
Up until 4 days ago, SAS was asking for 10,600kr for a bid. Then the bid price dropped to 4500kr. I placed a bid on Jan 11th. Got a notification today (Jan 12th) that the bid won - 23 hours before departure.
Happy that SAS lowered the price to something more palatable and that my bid went through with so much advanced notice. Even got to pick my favourite seat