Aged Pension Assets test help

Hi. My father resides in a dementia clinic and my mum recently passed away.

Whilst they were joint tenants on the principle home they have been seperated under Aged Pension for many years so considered single. Centrelink have been advised of mums passing and are now reassessing Dad’s pension as 100% of the home under the assets test.
I’m worried he will be cut off the pension immediately. His room in the dementia clinic is also a concessional room paid by his pension. He’s been there since 2019. The 2 year exempt period has expired and we were granted a ‘unreasonable asset’ exemption when my mum was living there.

The family simply don’t want to sell the family home of 60years. But we don’t fufil any exemptions i.e. anyone residing there who receive support payments, carer etc with no option to rent out as the home is unhabitable without major repair.
Any suggestions of what we can do? Last throw of the dice.
Thank you