I would think that the ANZ/Westpac facility will not have to...

I would think that the ANZ/Westpac facility will not have to decrease from its present level as pricing of the reserves that required the partial repayment of the facility would have been done at the low point in the oil price - and both Maari and Beibu have been replacing production with additional reserves - there should be a chance for them to redraw some more funds on the facility if the trend in oil prices continues.
It is interesting to note that this facility is due for repayment(or renewal possibly)in May,2019 so you wouldn't want the new bonds expiring June, 2019 so you would have to issue them for a five year period rather than three years.
They need to maintain their cash balance of $17mil for the next six months in order to avoid a capital raising as there are no other sources of financing available. In that regard, it would be important that they don't pay the bond holder any funds for the changeover of the bonds.