Gearing and pacing are your friends. I did the Triple Bypass last year and I am from Texas, too. Longest ride I did was 80 miles. I did SSB I & II and one week of Climbing Road Race. I thought I would be completely undertrained for it, but I used a 34 upfront with a 34 in the rear, paced it wisely and kept food in me. I was feeling so good at mile 90ish guys were drafting off me into a head wind. I didn’t use the 34 rear very much, but I was glad I had it, because it did come in handy a few times.
My problem was descending, everyone I passed going up passed me going down. I was so cold, I was getting bike wobble from shivering.