You don't give actual temp, as to being too cold. Most RVs will be useable down to the low 20sF. If your tanks are enclosed, you should be able to handle sub freezing temps. Not using your furnace, due to noise, may be your issue. Many RVs have a smaller heat duct that goes direct to the tank area. You may be able to add some types of insulation, such as Reflectix, or an extruded hard foam to needed areas.
My FW is rated 4-season capable, and is well designed for temps into the teens F. It does require use of the furnace to protect all plumbing, and is well insulated, even the large slide.
Jerry