What do you keep your thermostat on in the winter?

Me and my boyfriend like to keep in cold inside. We usually don't turn on the heat at all, but lately it's been getting below 60° in the house without the heat and that's just a huge no from the both of us. So we turned on the heat today since it's be a low of 15° tomorrow and decided to keep it at 67°. Is it odd that even when it's cold we don't ever put it above 70°? We don't like turning on the heat cause it's just makes the bill go up. Why heat up the whole house when you can just put on a jacket and use a space heater? At night we cuddle up under the blankets and we're just fine