In terms of long term care for terminally diagnosed patients in the UK, that is typically undertaken by unpaid close family members. They may also claim a carer’s allowance with is about £40 a week, so long as they ‘care’ for a minimum of 30hours a week.
Also, constant care maybe also paid for through using liquidated assets. And the Government will take a slice of that sale to cover your Dependant Residency Costs.
So in-terms of additional NHS Burden, it is just being offset over the later terms of the OS extension.