I have all the documentation on this dispute. 

I know it's a long shot, but I'm currently having lawyers review the signed subscription documents to see if there's any way to minimize the losses here. 

Here's a good folder setup.Bank StatementsCredit Card StatementsProperty Management StatementsMortgage StatementsSTR Platform StatementsInvoicesReceiptsClosing Documents (Purchase/Refi/Sale)LeasesCheck & Deposit ImagesVendor ContractsW-9’s & 1099’s

So, transferring title to an LLC is a transfer as defined by most mortgage or deed of trust documents as a trigger of the so called due on sale clause. 

When a tenant leaves, you document that they are gone, who remains, everyone's rights and responsibilities, how the lease will proceed, etc.

Document all your efforts, including repair invoices and communications, to show you’re acting in good faith as a landlord.

For a condo you can/should check the county assessor for land value  (you would apply the same allocation %, don't use their actual number listed) Also check your HOA documents.

If you need an option that isn't as document heavy, a DSCR cash-out might be a viable option if it's an investment property.

•Document everything – Ensure the transaction is structured at fair market value, with no special benefits to any family members.Bottom LineIt may be possible, but because of the family connection, the IRS could scrutinize the exchange.

If youre wanting to make a cash offer, all I can say is that Ive never seen a competent seller/listing agent accept a cash offer without proof of funds, meaning a bank statement or similar document(s) showing liquid cash for closing.