^^ all of the above.
Just remember: If you don't play, you can't win. Yes, you may indeed go bidless in recruitment, it happens. But, you could just end up with a bid to a wonderful sorority. And also, you may go through recruitment and realize that the NPC sorority life isn't for you (not likely, but it happens). The bottom line is, that if you don't at least try, you will never know what could have happened.
So you've got bags of time to put yourself in order for rush. You've got all winter to get involved in volunteering, to work on your grades, to plan your recruitment attire, to meet alums*, and to get recs. If you're staring out the window envisioning yourself walking across the quad with a big UT sweater on...don't let maybes stop you. Don't let hypothetical situations ruin your chances to be happy OVERALL. UT is a huge school, there will be tons of opportunities to find friends and happiness, both in Greek life, and without Greek life.
Go get 'em!
* note: if you find an alum and their organization is not represented at UT-Austin, they're still a valuable resource! Talk to them about their experience, ask their advice, and see if they can help you network with a friend from a sorority that IS represented at UT-Austin. Panhellenicism (is that a word?) does not end after college
