My Mum was also on board for that amazing event! The Captain said there should not have been any icebergs around, there never were, that time of year... The one which QE2 hit, he said, was not quite as big as a football field, more the size of a family house...
My Mum also told us that "Titanic" was showing in the Theatre that night!
She herself sat fascinated in her cabin watching the TV screen with the view from the bridge, showing the deck crew out with long poles, pushing the icebergs out of the way as QE2 advanced, slowly!
Those, at least, are my memories of my Mum's stories. I may amend this if she tells me some more or corrects my memories
Later edit : She has confirmed my memories, with the exception of the football field. The Captain said that the iceberg was not quite as big as Buckingham Palace -- more the size of a family cottage. Quite big enough, of course...!