I believe that artisanal chocolate is healthier than processed chocolate whose price is cheaper, so if I were you I would justify that purchase.
As for heating, I agree with you about keeping the equipment on. Forgetting is normal, we all forget something. And being you I think I would leave an area of the house warm. When you arrive you'll have to turn the heat back on and wait for the place to warm up, while you're cold.
You may be right about that. Those jams and juice definitely are because the juice is pressed cold and many are sugar free. The jam has more fruits than what you buy in the grocery store.
About the heating, the good thing is it heats up pretty fast, so it's not a problem, but if it is very cold outside, then it's best left on of course.