So last year I made a quick and dirty karo top quilt from some MOD down sleeping bags and some vaguely down resistant ripstop. It worked well enough down to -25C but is heavy and leaks down and not much use so I'm going to try and use the down (loads of feathers in it too :-\) to make a heavy duty car/ sled bag for winter.

But having spent all my time making lightweight kit I'm at a loss as to how to make a heavy duty TQ!

I'm thinking about using 1.9oz ripstop for the baffles (~3.5") and sticking with traditional longitudinal baffles but I'm stuck as to what fabric for the outer layer? Maybe a double layer of 1.1oz down proof ripstop?

And ideas chaps?