How long will flowers last in a car with water and still look fresh?

So winter banquet is coming and well i want to invite my girlfriend to go with me. I want to give her some pink roses and i can only buy them before school and cant give them to her until school ends. They would be in the car for about 9 hours with water. According to the internet the weather tomorrow is going to be about 62 degrees Fahrenheit. Will they last with these conditions?