I'm thinking of keeping my enormous dog in a tiny crate.
Why do you even have the dog?
The dog is a good watchdog.
An animal needs to be able to move in the crate so you cannot put it in a small crate. It is inhumane and could get you in trouble if reported.
It doesn't move around since I train it to stay put. It's a good idea to put it in a tiny crate. How else am I going to keep it in a bathroom?
The animal is going to need a larger crate. You should not put it in a crate that is too small to even move around in.