I put a small ss dish in the corner, attached to the side and elevated, sitting under a lixit (brand?) type dispenser. If the small dish goes empty, the dog uses the dispenser. The dish also catches any drips. Being in the corner, and elevated off the floor, it takes up very little space. Also, the dog (a visitor or foster) gets to drink out of a larger dish while outside the crate, many times each day.
If it's just a crate for the dog to sleep in during the night, I let him/her drink before going in, and don't worry about it during the night.