If you get away from the rivers, the Great Plains was a nearly impossible place to live year round. The cold fronts coming down from Canada with 50 to 60 mile hour winds, which are still quite common, would have been awful out on the open prairie. Along the rivers there was at least some firewood and timber for building decent shelters. Those people must have been extremely tough to have survived with only stone age technology.
They were tough, and they had low life expectancies; that is why I am so skeptical of high population estimates for them. I’d recommend reading the original “Little House on the Prairie” books to anyone interested in getting a feel for life on the plains; unlike the TV show, it was an autobiographical story by Laura Ingalls Wilder, and you get a real understanding of the hardships suffered by the original settlers in those areas.
The descriptions of children freezing to death walking home from school due to blizzards, or remaining in the schoolhouse burning all of the furniture while they wait out the storm, are incredible...
It was about 16 X 16, and the interior was dominated by a wood cook stove, the remains of a small table, a chair, and what we would call a day bed. the walls were planks, with cardboard on the inside, probably to keep the wind out and for just a smidgin of insulation.
You could walk about three paces at most without running into something.
Now, imagine spending your winter in those quarters--granted you'd have to go out for firewood/coal/whatever you were using in the stove, and to take care of the animals, to use the privvy (if you didn't use a chamber pot--which would have its own air about it, and to get water (likely from the pond nearby). No teevee, no radio, no internet, few books aside from maybe a Bible, and little entertainment. Meanwhile, the temperature out dips to -40 and the wind howls past your abode at 30 to 40 miles per hour...day after day.
Yep, those folks were tough. No doubt about it. I salute them.