I was in Antarctica with them, and I'm not sure if dress differs - I got the impression that Antarctica was more casual. But on our cruise few people dressed up.
Regarding wifi, the speed was ok, but they limit you to 1GB per cruise. An additional GB is $80. They said they are looking into increasing it since now they have Starlink. Maybe you will be lucky and it will be increased by the time you go.
I went to one trivia event and it was just ok. The cruise director did not have the teams exchange answer sheets for the results, so it was entirely on the honor system. Questions were very challenging - our team got 5/20 correct!