For five pounds you could have a much more flexible and safer system.
Example:
- 6 oz WPB bivy or 10 oz waterproof bivy (backpackinglight.com, etc.)
- 20 oz down jacket or slightly heavier synthetic
- 12 oz down pants (ligher ones are available; synthetic would be a bit heavier)
- 12 oz goretex Paclite shell
- 8 oz lightweight tarp or 10 oz poncho tarp (lighter ones are available), with lines and ti stakes
- 4 oz gloves and warm cap
- 4 oz closed cell foam pad
- 6 oz PSK with lighter, sparker, tinder, some first aid items