I'd do it.
1) There could be a schedule change, likely allowing you to change to a better flight
2) Do DFW, as there will be more options, and it's crazy fast to get to another gate there
3) Saturday is not too bad. I fly Saturday after Thanksgiving often and am almost always on time. It's Sunday that is the mess. As others said, weather is not usually a factor (unless DFW has the one random Nov. ice storm...)