My Tenant is terminating lease early - what are my options?

[Roderick McCleary]

Hi All - newer Landlord here. This is the first time I've come across this situation and was looking for any guidance/advice. 

My tenant (we have a great relationship, really enjoy them) informed me he bought a house and closes April 1. His lease ends Aug 1. I have his security deposit of $1,600 and in our signed lease it is stated "If the Tenant moves out prior to the natural expiration of this Lease, a re-rent levy of $1,800 will be charged to the Tenant"

What are my options here with this Tenant? Anyone dealt with this scenario in the past and what's my best path?

Thanks!

-Rod