It's been said that a "4-season tent" is really a "1-season tent", as it's much too heavy to carry and too hot to use in warmer weather.

What are the major advantages of a 4-season tent over a 3-season one? The obvious disadvantages are that it's more expensive and a lot heavier. But in a survival situation, would a 3-season tent reasonably suffice, if you constructed a snow wall as a windbreak? At what sort of temperatures would you say you absolutely need to have the 4-season tent? Or is it an issue of temperature alone?

I did a search for "4 season tent" on the forum and found a number of postings, but none seemed to answer my question. Chris K. did point out in one post that the 4-season tent is built to withstand a heavier snow load, which I must confess I hadn't considered. Are there other things that I missed? If I decide to go winter camping with a 3-season tent, am I dicing with death? Or am I just running the risk of being a little less comfortable?