I was snowmobiling one time with 3 others, and one of the sleds went a little off the packed trail and dumped over in 4 feet of snow. We had to stop and help. It would be hard to overstate the difficulty in moving around in snow that deep. Even though we could see the trail 20 feet away, it was all 4 strong men could do to get to the sled, tip it up and push/pull it back to the trail. We were all sweating and our hearts were thumping. Even in 2 feet of heavy wet snow, it takes a monstrous amount of energy to travel a relatively short distance. Like someone else mentioned, if he really wanted to stay out in those conditions, he should have camped early just off the snowmobile trail, and made a fire and a quinzee in a sheltered area near standing deadwood. Because he was wearing cotton, and had no blanket or tarp, he would still have had difficulties, but might have made it through the night.