My cousin camped near Leadville last fall and made the same call with a cheap pad. Woke up shivering at 4 AM because the ground just sucks all the heat right out. I see this all the time, people trying to save fifty bucks on gear that's meant to protect them. It ends up costing more in misery, or in buying the right thing later anyway. For real cold, you need that air gap and insulation, not just a thin piece of foam.
Leadville in October isn't exactly the arctic. I've slept on a couple of those blue foam pads in cold weather and been fine. A lot of it comes down to your sleeping bag and what you're wearing. People act like you'll get hypothermia if you don't spend two hundred bucks on a pad.