Having traveled from PIT-BOS every Thanksgiving save one for the past 6 (going on 7) years, Thursday morning and Sunday morning shouldn't be too bad. SFO-Houston will also avoid one of the worst aspects of travel at this time of year, namely inclement weather. Allow some extra time, stay calm (nothing worse than the panicked infrequent traveler complaining that his/her flight is leaving in an 45 minutes and he/she STILL hasn't checked in), and don't check any bags. Also, smile and be nice to the airline personnel.