Medium Term Rental Leasing - Month to Month or Set Lease Term?

[Ian I Leinwand]

I'm a experience property manager that is taking on a client with 10 medium term furnished properties for management. We currently manage 4 medium term rental and have some systems in place. 

My question is what type of lease terms work best to minimize vacancy and minimize the need to continually ask current tenants if they are planning on extending / renewing a lease. 

Currently we do 3 month minimum with an an option to renew for a set lease term - IE another 3 months or go to month to month. For month to month we require a 45 days notice to vacate

We are often contact by perspective tenants looking for specific time frame several months in advance but we typically do not know if the current occupant will be vacating or renewing. 

Would love to hear some feedback from BP community managing medium term rentals and or get pointed to some medium term strategy resources. We advertise on Furnished finder, zillow and our own website.