From the Cunard website
Queen Mary 2 and Queen Victoria
Yes, gentlemen can hire tuxedos including shirts, trousers and dinner jackets on board from the shops.
Tuxedo packages range from $90 for one night up to $250 for 5 nights.
Yes, I'm not a regular laundry user but the doors are locked overnight.
Opening hours are approximately 7.30 am to 9.00 pm but hopefully a more recent user can confirm.
From the prohibited list -
Emergency Position Indicating Radio Beacons (EPIRB), ham radios, communication scanners, hand-held radios, wide-band receivers, satellite phones, transformers, lasers and laser pointers
That's the way it used to work on Cunard but since the restart after the pandemic disembarkation has generally been straight from cabins at a time given.