It wouldn't be bad. I pulled up the flights for tomorrow to get an idea of what it looked like. Unless I miscounted, it appears there are 7 flights out of HOU and 8 out of IAH to DFW. First flight from both airports gets you to DFW just after 6a so you'd be able to commute in the same day for many schedules. Those flights can tend to be fairly full with lots of business travelers so I'd expect a fair amount of jumpseating. Out of IAH, you could always jump on a United flight. If you had to, you could hop on Southwest out of HOU and take the train from DAL to DFW. If you really found yourself in a bind, you could drive on those rare occasions when things were going wrong with flights, i.e. weather days. Any way you slice it, commuting sucks. But at least with that route the flight is short and you've got a lot of options.