Like they said "Insulate". Start saving. Spend some on insulation; ceiling first, calk windows, look at how well the doors seal, and improve on that if it's possible, then the walls. Hit every junky looking yard sale. Summer is a good time to find used wood stoves. There might also be a partial roll of insulation left over from someone else's project. And don't forget double wall or triple wall pipe to go througt the roof.