A few things I've learned for when your refrigerator is warmer than the air temperature you live in:
1. Don't be an idiot, dress in warm layers before you are actually uncomfortably cold. I use my wool fleeces on my chair and on my lap when I'm outside. At night they are on top of me in teardrop. We use a 12V heated mattress pad. Otherwise we have not used our portable heater.
2. Move your body: go for a walk, do push-ups and squats, go for a run. I hope I become buff.
3. Distract your mind: read a book. I read James Shaw's travel book about Tuscany. Good chatter about Italian food, people and life. Thanks Mom for the book.
4. Move your hands: cook. You will also be near the stove, a bonus by which you can warm your hands.
5. Right when you wake up and go to bed, put lotion on your face, neck and hands. Use face wipes. I will be making my own at some point.
6. Don't stop properly caring for your teeth. Flossing is now an acceptable bedroom activity.
7. Eat your meal before it's stone cold, which will be very soon. All our meals were done in bowls instead of a plate. Food stays warmer a bit longer in a bowl.
8. Wash your hands when washing the dishes. Also, locate hand sanitizer and handwipes in various locations around the rig, but do yourself a favor and use actual soap and warm water too.
9. Feminine wash is easy to make, and it's gentle on your bits. Rose water, witch hazel, jojoba oil, and few drops of Dr Bronner's and lavender essential oil. Don't be lazy, find a recipe online. Use it once a day. It's gentle enough that rinsing is not necessary. You will be glad you have an alternative to wipes.
10. Eat fatty foods. Do some guilt free eating of pork belly, peanut butter, buttered toast, coconut oil, nuts.
11. Pour some dish washing soap in a jar with a lid wide enough that you can scoop it out easily. Our soap is solid in very cold weather.
12. Coconut oil is ice hard at cold temps, so hack at it best you can and throw those "coconut nuggets" into your trail mix.
13. Warm yourself from the inside by eating warming foods and drinking warming teas and foods with ginger, cinnamon, cloves, black pepper, garlic, chili pepper.
14. Don't be stupid and walk around with wet hair.
15. You still need to drink water. Except who wants to drink ice water when you live in a freezer? Make yourself some tea and toss it in with the half frozen water in your water bottle.
16. Speaking of frozen water, inside teardrop at night, put your water bottle under the covers. Anywhere else and it will freeze.
17. Being warm enough is more important than looking good. "Hair by hat" is now a thing and I'm rockin it, I think.