Kate Winslet had some personal experience to help her with her role in The Mountain Between Us, out Friday.
The 41-year-old Oscar winner tells PEOPLE in the latest issue that she had no trouble believing the story of two strangers falling in love after surviving a life-threatening situation.
“I believed it because exactly the same thing happened to me when I met my husband,” she says of Ned Rocknroll, 37, her husband of almost 5 years. “He was a complete stranger, we met, and then the next day the house burnt down.”
In August 2011, the star was vacationing on Virgin mogul Richard Branson’s private Necker Island with her two kids — Mia, 16, and Joe, 13 — when a massive fire consumed the estate. She was able to make it out of the main house after famously helping Branson’s elderly mom down a few steps, while Rocknroll, Branson’s nephew, escaped a neighboring villa.
The two immediately formed a connection and got married the next year before welcoming son Bear Blaze Winslet, now 3, a year later in December 2013. It made for a fairytale ending for Winslet, who had been married twice before.
“I believe strangers can meet and their lives can change so much that they simply can’t go back to being the person they once were,” says Winslet. “[Ned and I] very much went through that together. Even now, I often times find myself looking for an item of clothing or a book or something and I go, ‘Where have I put that?’ And Ned will look at me and go, ‘Did it get burnt in the fire?’ “
WATCH: Idris Elba Says Kate Winslet Was Tougher than Him During Subzero ‘The Mountain Between Us’ Shoots
The actress relied on her happy family while filming the grueling movie set in the frozen Canadian Rockies. With just a small crew and her costar Idris Elba, the actress was excited about the physical challenge the role brought.
“I was really taken by the extreme location,” she says of shooting at 10,000 ft. in subzero temperatures. “I knew we would really be out there in the cold, and I was excited by the idea of that. I love physical challenges. There was also that kind of girl power feeling of being in my 40s and doing something life affirming.”
Still, the extreme location made her days heavy and she looked forward to coming home at the end of the day to her husband and three kids. The family turned mom’s work into a vacation, often using down time to play in the snow, ice skate on the frozen rivers and learn how to ski.
“I wouldn’t have been able to go and do this by myself,” Winslet admits. “I think I would’ve felt very far away and probably scared. But actually being with my little tribe, it takes all of that fear away. We turned it into fun. We treated very much like the winter wonderland that it was.”