The carry over cost with utilities and HELOC interest payments is about 1k a month.

The situation is the father/seller was previously renting out the house to his son until he stopped payment according to seller around August 2021.

After a series of excuses and delays, they are saying their bank transfer is coming through Monday and can send me payment then.

I'm wondering how many months of mortgage payments should I have in the bank to keep the house afloat until rented.

I used a private lendor to fund the re-hab (cash) and owner financed the purchase price (minus down payment) I have a bank account linked to Stessa and I see the cash deposit in the transaction tab. 

Onboarding was incredibly onerous and confusing (they'll schedule a phone call with you so they can have someone walk you through it), and once you get a reservation, communication with guests is difficult and they do not process payment for you.  

The typical acquisition profile is a luxury beach vacation rental in the $650-$850k range either with cash or 50%+ down payment from the sale of a property in another state.

He has been late on payment twice.

And determine how the payment and approval for work will be take care of before hand. 

You can take advantage of lower down payments but you just have to make sure of your numbers.