Huntsville, Texas is in USDA Zone 8b, which means Winter low temperatures as low as 15º F should be expected. That is cold enough to damage an orange (Citrus x sinensis). Ideally, it would be good to bring it indoors and keep in in a sunny window until Spring. However, if that is not possible, place the pot against a sheltered south-facing wall. Pay attention to weather forecasts. If a frost lower than 28º F is predicted bring the plant indoors. For light frosts, an unheated garage may suffice, but for deeper chills, say below 20º F it would be best to bring it into a heated indoor space. If the container is large and difficult to move, consider using a plant caddy with casters. If you use such a caddy make sure to insulate the space underneath the pot, as an elevated pot may be more prone to cold damage.