Your landlord is being on the up and level.
He already has 2 months rental deposit from you and you have 2 months left.

You are being honest with him and he's trying to screw you.

You could just pack your bags and just leave and just kiss the deposit good bye. Give the key to someone else to hand back to him, but make sure you take video of everything in case he accuses you off damage.

What can he do ? He doesn't even know how to chase you ? Tell him you are going to do aid work in Africa. Just make sure you change all your mail and redirect all your mail.