Anyway, so I found this one on ebay: http://cgi.ebay.com/1200D-TURNOUT-HORSE-HEAVY-WINTER-WATERPROOF-BLANKET-82-/250787496828?pt=LH_DefaultDomain_0&hash=item3a6419837c#ht_1657wt_1139

It's 1200D Denier nylon, waterproof-ish, 440g poly fill insulation, and its got lots of strappys.
I bid $40 max....got if for $39! Figured what's the worst that could happen.
So some of the components are cheap (straps, buckles, elastic straps), but the material itself is good and its pretty well insulated (pics don't do it justice).
Plus, the little flaps that normally would wrap around the horses neck to cover his chest, wrap nicely around the cowl to cover my inlets. Actually all the straps it comes with are adjustable and wrap up/hold it quite well.
I won't win any style awards, and It doesn't cover the bottom opening, but I need that open to pre-heat anyway. Not sure how will it will work, but has to work better than nothing, folds up pretty small, and should do an OK job of keeping the dew off.
Some pics: