If it’s cold enough to freeze your gas lines, you’ll be bundled up somewhere far away from your grill. Propane condenses around -40 degrees Fahrenheit, while natural gas begins that process at an even lower temperature. The only way your gas line would freeze is if water somehow made its way into the line, and in that case, the water would freeze before the gas. Regulators are more likely to freeze, but that’s still a rare occurrence.