If the ambient temperature in the room is in the low 70's then a glass tank is going to give you all of these problems as it's a poor insulator.

You can fight the laws of physics and continue to be frustrated, you can raise the ambient temp in the room to the mid-upper 70's (which coming into winter I suspect is not an option), or you can find a PVC or melamine reptile enclosure that will maintain the correct heat and humidity despite being in a cold room. Yes you will have to pay for the enclosure but it will pay for itself in time and energy savings, and it costs less than a vet visit to treat an RI because your snake was too cold and dry over the winter.