I’m in Vic. I always thought it was almost discretionary for the strata manager to consider interest on overdue levies. The one time I was going to be late I let my SM know in advance and gave her an approximate time of payment – it was due 31 December and I was going to pay on 14 January – she was fine with that approach. I think the key might be to discuss with the strata manager to see if they can work out a payment schedule that suits you and is ok with the committee? (So long as the OC gets the money in full and it’s not too delayed, I don’t see why they would say no).
The other complication for you might be that you are not allowed to vote at the AGM if you are in arrears on the date.