--but that's the nature of the game.

And, they aren't really going to consider your wholesale money as something that is stable.In the alternative, you may want to consider negotiating seller-finance/lease-option deals.

If you are the first person there, when the second person arrives, you will naturally start speaking with them.

I don't believe the distressed nature of the property will make a difference as a HELOC is really a revolving line of credit for you to use. 

Consider that by the distressed nature of the property, the back taxes, etc you can assume that multiple investors are bombarding the seller with mail, and most of that probably goes to the trash.

I didn't even consider the down to business nature of investing.

So, safest thing to do is probably send them written notice at their 60 to 30-day mark (sooner the better) that advises them, pursuant to the mutually agreed and signed contracts, since they failed to exercise their option to purchase they may now choose to transition into a month-to-month lease or move-out at the natural expiration of their lease term on whatever date. 

As to not catch unwanted attention from the mortgage lender regarding the nature of the transaction, and thereby possibly triggering the "Due on Sale" clause in the mortgage i tend to avoid unnecessary contact with them.

Make sure your sellers sign a memorandum explaining the risks involved in the transaction, and they're aware of the repercussions of informing the lender of the nature of the transaction. 

Alternatively, once you have the pin you could just go straight to the treasurers website.