Does anyone know of any other ways that we could mitigate or eliminate the risk of them not leaving prior to the October 31 deadline?  

100% agree with the prior posters to run away if those HOA and taxes are the annual figures.

I'd think you're starting off on the wrong foot thinking along these lines unless there is a agreement and significant assets in play that others may be entitled to, such as children prior to the marriage.

I strongly advise you to gather all the information and address prior to closing to make sure this issues will not cost you considerable time and money

Thanks @Rick Baggenstoss definitely want to get the property from the owner prior to the auction!

BillAs a prior commercial real estate lender for many years.

The instruction and prep to take the exam, the mentor and team that I joined at Keller-WIlliams Market place in Simi Valley + the added advantage of Bigger Pockets world =PRICELESS!!   

The manufacturer instructions on every brand will say the same, and if you want to do the flooring correctly it is a must.Good luck with your floor!

And you're absolutely right, those major capex can really eat up all that prior cash flow.  

Obviously, your screening criteria might be tricky, but you can measure income, longevity with prior rentals, longevity at jobs, eviction counts, felony counts, etc and arrive at a score using a formula.