The chance of them accepting is blind. No one knows until it comes back yes, no, or otherwise. Nothing in this market is determinable.
All the Best to you.
Lynn911 Dallas Realtor & Consultant, Loan Officer, Credit Repair Advisor
The Michael Group - Dallas Business Journal Top Ranked Realtors
If it was you, in the future don't put expiration dates on contracts being sent to lenders.
If it were me, I would rewrite the offer and get your offer price at least somewhat close to their counter offer. Otherwise you need to move on to the next home or wait out the banks natural progression of mark downs.