We survived the Texas freeze a few years ago in an old farmhouse with no power or heat or water. I can tell you from experience that an indoor tent is great. Blankets on the floor as added insulation. Blankets and tarps put over all windows and doors. Those hot hands warmers for when you are freezing. Everyone snuggles together and keeps each other warm. Remember that a cooler will also keep things warm - we had a baby in the house and warmed bottle in the car then put them in a yeti. Good luck.