Should I just get little whit bins with lids, and heat tape/t-stat?

Should I skip on the aquarium, and get bins/drill holes?

With a snake cage like this, what kind of sub should I use?

I don't want the snake to burrow all the way down and burn its self.

use newspaper for substrat just lay it out flat and a rheostat to control the temp. Place the UTH at one end, covering no more the 1/4 of the tub. Adjust the rheostat so that it is never more than 90 and your snake will never burn.

Tubs are great for holding humidity, tanks not so great.