Sharing my QM2 “bid to upgrade” results here since I found this forum thread helpful in my decision to submit my own bid a couple of months ago:
Voyage details: QM2 Transatlantic in May 2024
Offered to upgrade from a (Guaranteed) Britannia Balcony (Sheltered) to a Queens Grill Suite (Q5).
Offer status: Accepted! (my bid was in the lower half -but close to middle- range between the minimum and maximum options)
I put in the bid on 2/28 and got notified yesterday (Apr 3rd) that it was accepted (<50 days before departure)