Thank you for your insight, these types of shelters are really cool, thought I feel that they are a bit big for backpacking. The use of a fire for warmth is awesome, but very specific to types of hikes... especially when/where you can build a fire. Then again, getting up to keep it going.

My family, since I was 6, are historical re-enactors of the 'French and Indian War' (pre revolution) and The Revolutionary War. This has included many canvass based tenting experiences in all weather. With my father and some others I have done period scouts in Maine in mid January with temps at 0F and below, we did two lean-to shelters of canvass apposing each other with a narrow 6' long fire in the gap. With lots of wool, shifting in the night, stoking the fire, it was ok. The more insulated/modern version seems ideal, but still limited to fire use.