I'm not sure if this would work or not.
On one hand, Texas is a big place with lots of people (and therefore could contain a lot of NGers). Hell, I'm willing to bet that Texas contains more than 300 members.
On the other hand, there are a lot of problems. Texas isn't like the UK or New England, where tens of millions of people are condensed within an area smaller than 1/2 to 3/4ths the size of Texas. There could be transportation problems (if the location is on the opposite side of the state, you're almost entirely screwed from the get-go if you're unable to drive) or money problems (you'd have to pay for more than gas if you live outside the city it's held in), and that's just off the top of my head.
On the other hand, most of this could be fixed with the right person/people organizing it. If it ends up happening, then I'm all for Houston being the meeting place.