It’s not safe to drive a car on 6 inches of ice. It’s enough for a snowmobile or single-person ATV. I wouldn’t drive a car onto a frozen lake without 12 inches of ice, 16 inches if it’s a typical half-ton pickup.
I live in MN and have slept overnight on the ice (inside of a heated trailer) before.
I live in MN and have slept overnight on the ice (inside of a heated trailer) before.
https://www.dnr.state.mn.us/safety/ice/thickness.html