The buyer has until the closing date to come up with funds for the A-B transaction.

I thought that I would just set a close date out for 3 months to give her some time, but she'd like to get the sale done as she also owes back taxes and is tired of hearing from the County Trustee's office.  

@Christian Wathne The two flips are dated mainly.

I have several buy and hold properties where it's clear as day that the in service date is the date the property is available for rent. 

I would tell them that you are happy to enter into a m2m lease with them if they are paid in full at a certain date.

Fact is, most investors get discouraged when they tour Class C & D properties.

(different story if due date is on the 1st and he pays the 15th, then that is an issue)4.) let him know I'm the owner or property manager?

I toured the house and it was shockingly clean.

But check what your current lease says about extensions: some leases automatically extend on their current terms unless termination notice is provided by s certain date.  

I realize this thread is a little dated, but I found it useful.