Mike Schumann wrote:
I suspect that the chance of loosing lift in a glider is significantly
higher than loosing an engine. I personally do not think it is a good idea
to fly at night in a single engine power plane unless you have a full moon
and are over very favorable terrain.

In a typical 15M glider, if you can climb to 17,900 ft MSL an hour
before sunset (which is not uncommon in the western US), what time will
you land if you glide at best L/D to your home airport at 5000 ft MSL?