McDonald's frozen drinks are designed to be enjoyed in their frozen state, typically served with a straw. If you were to put a McDonald's frozen drink in the freezer, it is unlikely to melt completely. The freezing temperature of the drink, combined with the additives and stabilizers used in its preparation, helps to maintain its frozen consistency. However, over time, it may become less frozen and start to thaw slightly if left in the freezer for an extended period. The specific time it takes for this to happen may vary depending on factors such as the freezer temperature and the composition of the drink. It's important to note that freezing a McDonald's frozen drink can potentially alter its texture and taste, so it's recommended to consume it as intended for the best experience.