Avoid I-35. Ha!
You might also consider staying somewhere like Fredericksburg. Fun little town to knock around in. Lady Bird Johnson Park is a nice reasonable place to stay. It puts you about an hour from Austin and San Antonio.
Lockhart has a couple of pretty famous BBQ places.
2016 Ford F150 Platinum
2013 Coachmen Freedom Express 233RBS
Prior: Jayco Pop Up, Shasta Bunkhouse, Rockwood 2560G Pop Up