Ann: Weekly NAV Estimate, page-19

It's not quite that dire. From the Notes III prospectus:
Unless Redeemed early, URF Notes III mature on 24 December 2021,representing a term of approximately five years (four years and 10 months)from the expected Issue Date. See Section 2.2 for information aboutcircumstances that may give rise to an early Redemption

And:
The Issuer may elect to Redeem or partially repay all of theURF Notes III on the First Call Date (being 24 December2019) or any Interest Payment Date after the First CallDate. Any partial repayment will reduce the outstandingFace Value of each URF Note III and will be paid to URFNotes III Noteholders on a pro rata basis on the relevantrecord date.

So in fact Notes II in December 2020 is the next big redemption date.

Based on current operations there is no way they can accumulate sufficient free cash to redeem Notes II or Notes III when they reach term. They will have to raise cash for redemption.