Bobb - here are my thoughts:
1) You should not be cold like that. My feeling is that If am ever cold while I am out in the mountains, one of two things is going on: I've blown it; Or I'm in a transition between activity levels and amounts of clothing and haven't quite adjusted yet (like when you start out a little cold because you took off a layer knowing you're about to go up a big hill and you'll warm up soon). If you are hanging out in camp and you are cold, you're not wearing the right clothing for the conditions.
2) Bivy sacks add a little warmth, but not much, except for when you are actually sleeping outside a shelter and the bivy sack is cutting the wind - then it can be significant. If, instead of carrying a bivy sack,you carry a sleeping bag with added insulation, that will give you more added warmth than the bivy sack for the same added weight, assuming you ar in some sort of shelter (tent/cave/igloo, etc).
3) Gloves go in the sleeping bag with me at night. Shoelaces - well, this no longer applies for me since my skis boots have buckles and not laces, but when I did have boots with laces I used them as underlayment for my pillow or placed them between my tentmate and myself, and never had frozen laces.
4) This happens all the time, and it's pretty much habit for me to pick campsites that up of the valley bottom a ways to avoid it. It doesn't usually take much to make a difference.
5) It isn't fun anytime the conditions are beyond what you are equipped for and prepared for in terms of experience. So the real trick is to know what temperatures are too low for your gear.