I trhink I answered it as well
read the lease - if there is no tenant break clause then you should wait until the end of the lease ( and pay ) but things are always negotiable
if it is a run-on lease then it is the period of the rent - monthly rent, give a months notice
and ..... since then
one of my tenants have given 8 d notice to leave on 15th Jan
and my main fear is that .... she will decide to stay on.
Possession is the great thing - move on, cut losses and let it to someone who wants to live there and pay rent