This will depend on how large your house is. But to give you an idea, a wood burning insert with more than 100,000 BTUs per hour can easily heat up to 3,000 sq. ft. of space, given that it is well-insulated.
Just remember, the higher the BTUs, the higher the heat output will be and the larger the space it will be able to heat. You can use this free calculator to learn how many BTUs you need to warm up your house.