High in the sierra nevada mountains in winter with the outside temperature around -5F I frequently saw 0% humidity. The fine tip of the hygrometer needle rested solidly on the pin.
Static electricity sparks, pass hand across sweater it clung.
It was when I started waking up in the middle of the night with a bloody nose that set the final straw.
I boiled water on the kitchen stove to gain a handle about what was needed. One burner lit under a turkey pan boiled off 2-gallons of water in about 40 minutes. In a 560 sq ft living space it raised the humidity to between 45 - 50% with an air temperature of around 65F.
It took hours for the "47%" dropped to less than 20%. But it gave me an idea of what I was facing. Ice will form on the inside of uninsulated glass.
The stove and a pan of water and a hygrometer can give a pretty good idea of the amount of water and the amount of time needed to get things above 20% R/H.
This narrows down the guesswork.
But again, I never will allow myself to be put in a position of having untreated cold air humidification. Just taking a breath felt like I was inhaling lava when I had pleural pneumonia.
Only the malamute enjoyed weather like that. He'd stick his nose under his tail on the concrete walk. Curl up and allow 2-feet of snow to pile atop him. Next morning, I would open the front door and a huge mound would arise then scatter as he shook the snow off. Attaboy dog food, one trout in sauce heated to around eighty-five. He was convinced he was in sled-yanker heaven.
He would then approach the door to receive a pat on the head. His coat would be crackling standing straight up. Pass a hand near the fur and it would stick and tingle.