hm I don't know really I am just throwing in the ball park here but I would say 30 to 40 The 30 is when you have a good cold tollerance and you bunch the under quilt nice and tight and you don't have wind chill. Maybe I am pushing it with 30.
Bacon and Camping makes me happy.
"When life gives you lemons throw them back"
I camp in bear country and I am a bear Burrito.