When you're in southern New Mexico you don't automatically think of cold weather. It was 35 degrees this morning.
I'm originally from Michigan. I've vandweller in sub zero temperatures safely two winters in a row. It's not my favorite thing to do, but I am one of the experts on winter weather Vandwelling while not hooked up to any power sources.
In the morning, move van so that you're either parked facing due east or due South, or any spot in that range. Passive solar heat (the sun) will quickly have the van warm enough to crack windows for comfort.
Dressing for the weather (remember I'm a woman and my experience reflects that)...I love layers. Tank shirt, t shirt, then a sweatshirt or sweater or long sleeved shirt. Flannel shirts rank high on my list. Warm socks, leggings, a skirt over that. Fingerless gloves and stocking hats are definitely part of my wardrope. And I really love those $1 stretch gloves. As the day warms, I peel layers off.
It's now time to open my back door and get my soft boots that smush into a little spot. Warm head, hands, and feet mean I stay warm.
Sheets are nice...in a house or a fancy rv. I prefer a fleece or micro fiber plush blanket...inside my sleeping bag (which I actually zip up in cold weather). A small $3 fleece blanket lightly covers my face to warm the air I breathe.
Yes, I have a buddy heater. I've actually stored it away in my travel trailer that's currently in a safe paid storage lot.
I go to bed early and get up when Sun is up. I'm retired so generally I can choose my own hours. No clocks or watch necessary most days.
Learning how to adjust and adapt to life rather than forcing life and climate to adapt to me.
Good Coffee To You
See ya down the road