I've worked for three (four?) airlines, and at none of them, including cheap-ass Pinnacle, planned with so little gas that it would be an issue if you flew faster than plan speed. I think you're overestimating how much extra fuel you burn. For example, in the CRJ-200, flying 310 indicated instead of 290 indicated over two hours (a pretty long flight in an RJ) would result in an extra 800 lb fuel burn. If memory serves, we usually carried about 1,200 in contingency fuel and another 1,400 in reserve for a cushion of 2,600 lbs in extra fuel. If you're puckering up at 2,600 lbs of extra gas in an RJ, then you might need to have your man card revoked.
Oh, and Whataburger (and everything else in Tex-ass) sucks.
@Seggy