titanium dude - sorry i missed your earlier post for so long. not sure how the bag would cope on its own, its pretty lightweight material. in a bothy you'd deff need ground insulation. on a hot summers night you'd have no problem heat wise (although i don't think i'd get in mine without a long tshirt and trousers on!). i use mine directly on the ground with an inflatable sleeping mat inside the bag and my sleeping bag on top of the mat. this one seems to be gortex all over.
i'd be tempted to try staying in it with just a silk liner for the warmth / comfort factor?