I hunted Pedernales a few years back. I was successful in taking a doe. During my hunt there were no exotics spotted other than a few feral goats up in the high rocky areas. Several folks killed deer, and a few killed hogs.
The assigned "blinds" were little more than cedar piles during my hunt. Some were good, some weren't. My advice is to try your first location for a day and a half or so. If you haven't found much sign (tracks, droppings) or seen anything at that point, you might try to change to a more-productive spot. My first spot was terrible, but my second was pretty good. If you have deer in your area they will find the corn.
The workers there can be helpful, just depends on who's there.
Best of luck to you.