If you go this route, then I recommend you notify them well in advance (90+ days) and offer them the option of moving out early without penalty.

My initial thought is to write it as an addendum with specifics of how many weeks a year, max duration, rent will be prorated that month, dates must be agreed upon with tenant at least 3 months in advance, etc Thoughts?

Thank you for the help in advance!

Thanks in advance. 

Thanks in advance!

We had previously paid the contractor after work had been finished and after some time, we paid the fourth one in advance. 

No one would give 30k in advance of closing and no one would be posting all this BEFORE closing if they were a participant in the process along the way.

Thank you in advance, all advice is welcome!

Thanks in advance

Quote from @James McGovern: I no longer entertain buyers agents from CaThere can be many bad players in any transaction.