Inherited tenants' lease expiring same time as closing

[Len Ulish]

Hi all,

I am under contract to purchase a duplex that I am going to househack.  I am scheduled to close near the end of May and the current tenants' (one unit occupied) lease is expiring May 31st.  The language in the current lease indicates that their lease will renew month-to-month if tenant or owner does not provide written notice at least 28 days prior to expiration as to any changes.  

The tenants have indicated that they would like to renew.  I am going to have them complete an application and screen them before I would have them sign a lease.  But it is obviously very close to 28 days before current lease expiration (if that ends up being a factor in this case).  I do not know if I have an obligation to honor the month-to-month renewal terms of the current lease since I do not even own the property yet, though I suspect I do.  I also don't know when is appropriate/legal to have them sign a lease prior closing...possibly with some type of 'subject to closing' clause in the lease? 

Based on limited interaction with the tenants, I would be interested in having them sign a term lease, assuming they pass the full screening process. 

My decision to complete the purchase and close is not dependent on these tenants being suitable to stay long term, so that is not a question.  Just looking for the best way to approach the current/new lease situation.

I'm speaking to a real estate attorney tomorrow about my obligations/options but figured I would receive some wise words here. 

Thanks!