Should I install a propane fireplace insert?

Your inventory indicates that you have a late 1970s single-story home of approximately 1500 - 2000 ft.. It also indicates that you have electric baseboard heat and a gas fired water heater. If the water heater is natural gas, a natural gas fireplace insert may make more sense than propane. If your water heater is propane powered, you likely already have an acceptable propane storage tank. A propane fireplace insert would probably not provide adequate heat for the entire house during a power outage, but it would almost certainly provide enough heat to prevent freezing pipes, and it would likely provide enough heat for living and sleeping in the room containing fireplace. With a propane fireplace insert in place, you will have a hedge against soaring electrical costs. You will be able to favor propane or electricity depending on their cost per BTU of output. Bear in mind that electric heating is approximately 100% efficient. Every BTU generated stays in the house. A propane or gas fireplace insert has an input capacity and an output capacity. The output capacity dictates how much usable heat you will get. The balance goes up the chimney. Some fireplace inserts come with limited ductwork and fans to distribute the heat. While this might help to offset high electricity costs, the electrically powered fans will be of no benefit during a power failure.