Cate Blanchett spoke with HFPA journalists in 2004 about playing Katharine Hepburn in The Aviator directed by Martin Scorsese, with Leonardo DiCaprio as Howard Hughes.
“Kate Hepburn was a deeply private woman, so we were trying to unlock the human being while also watching her body of work and paying nods to certain performances. Marty and I talked a lot about Bringing Up Baby and those screwball comedies that she made with Cary Grant, where the dialogue was really fast paced. The wonderful thing that Marty offers is his love and his knowledge of cinema, so he screened quite a few of her films for me, which meant that I could really study her performances, particularly in a close-up on the big screen, not on a TV screen. Martin Scorsese is an absolute genius, he’s a perfectionist and a gift to the cinema. I just wish he would make more films about women…”
“I was trying to chart Hepburn’s development into who we iconically know her as, which is when she hit the screens in Philadelphia Story, that’s when our sense of Hepburn as a woman and as an actress crystallized. So for me that was the moment when she left Howard Hughes, because when they got together, she was box-office poison and her career was floundering. She’d made a lot of failures and Hollywood didn’t really know what to do with her. The story of their relationship in the film is saying that, as she became more truly herself as a performer, she outgrew Hughes.  But it’s all speculation, because their affair was so clandestine that there’s not a lot of fact written about them, except that they went flying together, and no-one knows why they broke up.”
“If you read Me, her autobiography – and I don’t know if you can believe a word in anything that somebody writes about themselves – she says that they were too alike to be together. They were both very ambitious and interested in pushing themselves through boundaries and breaking into new territories. She stretched what it meant to be a female actress in Hollywood, and that was a really brave and powerful thing, in the same way that Hughes made American business come to him.” 
“I was playing Kate from ages 28 to 40, so I took a lot of cold showers, because she used to break the ice going swimming in her place in Upstate New York. I took up tennis again and I started playing golf. I felt the need to be athletic, because if you look at her early films like Spitfire or Sylvia Scarlett, there’s such an exuberance and energy, that then she learned how to harness.”
“I find her fearlessness very inspiring, because you have to risk failure, otherwise you don’t keep developing. She had enormous failures, but she kept going, she wasn’t a frightened woman, so I admire her desire to be true to her own tastes as an actor, and her tenacity. I find the breadth and the dimension of her career incredibly inspiring, so I hope I’m like her.”