Jeff
In general, for cold weather camping, the size of the tent you will use will be determined by wether you are going to have a heat source in it or not. If you want a large tent so you have room to move around, a canvas cabin tent works well, but you will want a heat source like a wood burner or propain heater, the canvas (at least the sides) are breathable and as mentioned canvas is much less suseptable to sparks than nylon or polyester.
If you will not have a heat source, the smaller the better. Two people in a good quality 4 season 2 person tent will stay much warmer than 2 people in a large tent like the one in your picture. I've done this in temperatures down to almost 0 and haven't had any problems, but I have spent many nights freezing my butt off in a pop up tent camper I used to own.
A few things to think about.
They now make propain heaters with oxygen censers on them that will turn off when there is to much carbon dioxide in the air.