You can use tight woven fabric as a wind block and spray shield. It is what you want. The trick is to ventilate on the downwind side.
Since you said you use an SPE you might want to use something like the Hennessy overcover:
You can also use something like this as a wind block/insulation/moisture barrier:
I have use the blankets as both a ground sheet and an over cover. On top just don't completely seal the lee edge and it ventilates enough to avoid problems