The SOL Escape Bivy is OK but can certainly be made better with some mods. My two biggest complaints are that it's too small and not breathable enough. There's not much I can do about increasing the breathability of the fabric but I did come up with a way to make it bigger.
Basically, I:
- Got some foam sandwiched between space blanket;
- Marked a centre line down the exact middle of the back of the Bivy bag from near the head to almost the foot;
- Cut the bag done the centre line;
- Opened the back of the bag up about 20cm and then taped it down from the inside to the space blanket backing using aluminised reinforced adhesive tape;
- Cut the space blanket backing into a mummy shape matching the outline of the new enlarged bag;
Sources
I got the foam sandwiched space blanket from eBay and as for the bivy bag, the best price I've been able to find recently has been from Amazon for around $30.