"Just out of curiousity...has any pilot died of exposure after landing out?"

Yes - many. That answer is in response to the word "pilots". As to
sailplane pilots, I am not sure. Sailplane pilots tend not to fly during
inclement weather in the middle of winter, so the odds improve.

I teach survival classes to our Search and Rescue group. The most important
things are food and water - then heat. Knowing how to start a fire can be
critical when the weather is inclement. A few years ago we found a hunter
and two sons that were suffering from severe hypothermia. They had many
matches but could not start a fire.

The soaring pilot has a lot of things going for him, especially with an ELT.
Perhaps the most critical thing is hydration. Without it, you can die in a
couple of days. If you keep other pilots informed where you are, you are
unlikely to be missing long.

Colin