Living in MN it is difficult to minimize impact over the winter months. But keeping the thermostat at 55 degrees is doable if you have enough blankets and get in the habit of wearing more clothes around the house.
Insulate windows in the winter. I use wool from my sheep and paper from my schoolwork. I also use plastic from window insulation kits. There is definitely a trade off here as I am using plastic. However, it really helps to seal off infiltration (saving on heating expense and emissions) and can be re-used every year (with occasional patching).