Yup, not necessarily the most comfortable way to spend a cold night but it still works. It must've been a lot more common in the past. I know some oldtimers who used to sleep outdoors just wrapped in a woolen coat, big blanket or a shelter half (which they would also use as a raincoat) unless the weather was very cold or wet.

Nowadays with more gear available though I think a light sleeping bag combined with a poncho would be a better (more comfortable) choice. A bivy bag more so, but it tends to be more expensive.