Welcome to AF.
By your symptoms, you most likely have a bad ignition switch (common Cavi problem). The contacts get weak and start to drop circuits. That's why your radio still works, but the guages don't.
Before getting too far into it, check simple things like the battery itself. If you're in an area getting hit by these sub-zero temps, an older/weak battery could have frozen, causing an internal dead short. This can allow low amperage current to circuits like the radio, but not enough for the starter. Many times when batteries dead short, they will draw any power being supplied through the jumper cables and not allow enough for a jump start.