I've heard of people doing this for retics. If you really want to make it cool, turn the tub into the water dish, large enough for most snakes to take a swim. Then add a recirculating waterfall, why not. That will fix your humidity issue. Leave the tub drain active for easy cleaning. Now that sounds like it has potential for a bad ass snake room!
That's an amazing idea! I was just worried that a smaller snake might be able to get through the shower drain grates or a bigger one could potentially push up a loose one. I'd get a retic I suppose, the Burm seems too big and powerful for a bathroom.