Driving to the Eclipse in Texas 2024

So I’m planning to stay in Austin or Dallas for the 2024 eclipse, and ideally I’d want to drive further under the totality.

How sane is this as a plan? Should I expect gridlock on the highways as everyone and their dog drives in or moderate indifference? (last time I stayed in Nashville and just walked to the stadium so I didn’t deal with the traffic (though there were absolutely no rental cars to be had the next day) :-}