It will be the way I go when my time comes.
I have experienced mild hypothermia, though not at subzero temperatures. It was in 1976, when I and two companions had to cross a shallow but fast-flowing river coming off an icecap in the interior of Iceland. I went first, on a rope for safety, while my two companions stayed on the bank. The current swept me off my feet a few times, and I got completely soaked. Very soon I could feel my strength draining away, so I turned around and headed back to the riverbank. By the time i got there, I was almost helpless. My companions fished me out of the water, put me into a sleeping bag, and lit the stove to make a hot drink for me. Because I wasn't in the water very long I was back to nomal within an hour. It wasn't a partiularly unpleasant experience, but what shocked me was how quickly I lost my strength.
In water close to freezing point your survival time is about 30 minutes.
However, hypothermia in water is not the way I will go. I will head off into the wilderness and fade away more slowly. You can die of hypothermia in air at temperatures a little above freezing, especially if it's wet and windy, and of course you can die at temperatures well below freezing even if it's calm and dry. Eventually you stop feeling cold, you start to feel warm, and basically you go to sleep and don't wake up. It's peaceful.