The blankets were taped together beforehand. If you used something like gorilla tape, I think the blanket would fail before the tape did. The whole deal looks about softball sized.

He has the bottom sealed with snow, presumably you could use logs or rocks to anchor the bottom, but I do have my doubts how it would hold up in high winds, but then any tarp in high winds is going to have problems. You could gorilla tape in 550 cord loops for anchor points.

Of course, it does depend on found materials and a fire, but its not too bad for something that fits in two coat pockets.

One could rig something comparable with a tarp with a silver reflective side, that would be more durable and easier to anchor, but nowhere as compact. Also, there is no reflector on the fire, which would improve efficiency as well.