First off, stick that probe under the substrate and reset your thermostat accordingly. You want to measure the hottest point your snake can get too. If it is 93* on top of the substrate it will be much hotter under the substrate.

77* is a fine ambient temperature. There is really no way to raise it unless you use an RHP, another UTH, or some kind of lamp. You could also use a space heater but a space heater in Texas makes no sense

You can make more holes if your humidity doesn't go down. I try to keep them at about 60-70%