Because it's too cold, they appropriately shortened their travel time.
In the afternoon, as they walked, they'd camp whenever they found a suitable spot, without waiting for evening.
A good camping spot is warm, comfortable, and convenient.
A place sheltered from the wind is definitely better than one blown by the northwest wind.
Set up the tent, block the wind, dig a pit in the ground, and make a fire in the pit.
This way, it's relatively safe.
As long as the fire is big enough, the tent will be warm inside.
As for how to vent the smoke.
Don't consider the smoke venting issue.
Then won't the tent be smoky and dirty?
Yes.
If you really dislike the smoke, dig a trench fire first, use stones on top to seal in the smoke, lay soil, and then set up the tent.
The ends of the trench are outside the tent.
Thus, smoke is vented outside, and inside is warm without being smoked. Lay mats on the soil, and it might even be too hot to sleep.
Fourteen people with three tents.
