I agree, if they want to move then so be it. I don't want to make someone live where they don't want.
Depending on the Tenant I don"t always mention early termination penalties. Why, b/c the hopes of getting the deposit back will encourage them to clean before they leave. I play the "Oh, I am sorry to hear that. I sure will miss you". I have waited until they are handing me the keys to say anything. Once again, it really depends on the Tenant. Had one Tenant move early for family reasons (death in family), apologized repeatedly, and told me to keep the deposit. Had one move this past week (early termination) and not even going to charge. Dad is a friend/painter has done work for me in the past. Has saved me mucho $$s. Not only is the place clean, they even pressure washed the porches!!