My tenants are all good. We haven't had bad ones yet.
We ran into this issue serveral times, some tenants bought new houses, some had to move out because the relationship didn't work out.
That is our answer: " We totally understand your situation. Yeah, We would have done with same if we were in your shoes. Unfortunately, since you guys leave earlier before our lease, it puts us in a difficult situation. We would try our best to find a new tenant, The best scenario is that we can find a new tenant right away and give back your security deposit. If not, we probably need to keep the security deposit to offset our loss."