Welcome dufurgirl
If you have access to straw you could pile some bails up on the outside wall of your bathroom. It would help allot. A small catalytic heater in the bathroom would be cheaper to run than your furnace and give off co2, just have to get a safe reliable one.
Thanks Jingo. It would be a pretty tall stack of straw it's our 5th wheel and it sits up high in the driveway. But that is a great insulation I used to use it years ago around the skirt of a trailer home I lived in back then. I figure if it gets too cold I will just remove the vent hose from the light and vent the heat right into the room. Harvest should be right before Christmas. Fingers crossed the temps don't go too low. Holy moly we got below zero in Washington State a few years ago in December.
![Aweath :snow2: :snow2:](/data/assets/smilies/snow2.gif)