rayporter
WKR
you are doing the right thing to discover what works now. I am confident you wont freeze when the chips are down.
here is a couple other things to try or be aware of. the pad. it is easy now to add a pad on top of your pad to test what many have suggested[ a pad problem] it only takes a quarter inch to three eights inch added on top to be sure.
you can make a mantle of material such as polar guard or any insulation you can get at a fabric store to go over your bag. a 3 ft by 6 ft piece can be velcroed to the top to add a generous amount of insulation and help your temperature rating by several degrees. it could even be velcroed into your bivy. heck an old poncho liner tied over your bag would give a quick test on a cold night.
luck-ray
here is a couple other things to try or be aware of. the pad. it is easy now to add a pad on top of your pad to test what many have suggested[ a pad problem] it only takes a quarter inch to three eights inch added on top to be sure.
you can make a mantle of material such as polar guard or any insulation you can get at a fabric store to go over your bag. a 3 ft by 6 ft piece can be velcroed to the top to add a generous amount of insulation and help your temperature rating by several degrees. it could even be velcroed into your bivy. heck an old poncho liner tied over your bag would give a quick test on a cold night.
luck-ray