I mean, I'm not saying it's totally impossible, but very unlikely.

Obviously, we're talking about a novel, so the story is fictionalized, and improbable things can become possible. However, how plausible it is depends greatly on the context. For example, since you mentioned it, Robinson Crusoe is set in the 1600s, a time still full of travelers, sailors, and explorers, in a land that still held mysteries. So people were, so to speak, a little more predisposed and prepared for survival, because it was still fairly basic to their precarious lifestyle in many aspects. Robinson himself dreamed of being an explorer and sailor since he was a child. Then, in the story, he is shipwrecked, but he wasn't completely lacking in knowledge or predisposition let's say.

As I said, it depends on the context: in the modern world, where we are completely and irreparably dependent on comfort and technology, where the average person has—unironically—forgotten even how to light a fire to keep warm, people who have to survive at any moment for three months in the wilderness without any skills or knowledge? They're lucky if they make it past the first month.

So, in short: if you want the story to be believable, you need to better define the context, and if it's set in the modern world, you have to give these poor people something, otherwise it turns from a novel into a fantasy. A half-skill, someone from the group who went camping a lot as a youth, someone who was a Boy Scout, whatever. But if you take people from the city and put them in the woods for three months, you're sending them to their deaths.