Well, I'm not regional but know that Skywest and XJT both domicile in IAH. There are a fair number of UAL commuters who fly out of IAH and I've flown with a few pretty senior CAs who do it. I've done the IAH-SAT turn a number of times in the 73 (~4 times). They're usually pretty full but I have never had a jumpseater. Long call would be pretty easy. Short call would require a crash pad. Worst case you can make the drive to IAH in about 3 hours.