@VideCorSpoon,
The A-frame shelter you mentioned is also called a debris hut. I have built literally hundreds of them (many with students while teaching). They are easy to make and cozy and warm to sleep in. Tom Brown details them in his book.
The ICEBOX seems like a neat invention, but in a survival situation most people would not have the equipment. The Inuits have lived for thousands of years in igloos. They are successful because of the strong winds on the tundra. The snow is strongly paced.
Instead of a snow cave as mention in the website, it is best to build a Quintze hut. However it is a lot of work. You have to pile the snow first and let it settle. Place sticks in the snow mound about a foot or so long. Start digging out the inside using the stick as markers when to stop, to make the walls about a foot thick.
In our society, survival in the wilderness isn't that important anymore. I find it an interesting hobby and a challenge to be able to live like the first people of our country.
Majic