Ficus typically take a lot of punishment if you are in a mild climate. You can chop below the last green, but I wouldn't risk it because Ficus typically back bud quite well. So, I always leave the lowest green and cut above that, then wait for more back budding if needed. Because typically with Ficus you can grow and cut back several times in the same season, I haven't seen the need to cut back to the base and hope it grows back; I'd rather just cut above the last green and be a little bit patient.
I just checked the 7 day forecast for Tweed Coast and it looks like you are getting temps which are warmer than Sydney. So, you should already be seeing some Spring budding because all of my Ficus are already throwing out new growth and back budding. Playing the waiting game is a matter of weighing up options with a Ficus, you can decide if you want to sacrifice new growth (in the pipeline) / ramification for the chance to jump in early to build new direction and branches.
My opinion and experience, you decide based on your circumstance / don't blame me if your trees die:
If you chop now you will lose some of the stored energy in the new growth which could build more ramification, but you can start early on building new branching. If you have healthy Ficus they are not going to sulk if you don't wait for existing buds to push out growth and harden off before you chop. Some species will not be happy if you hard chop when they are beginning to push out new growth. They make an investment in new growth and if they don't get a return on investment they take a hit. Ficus can take the hit because they have stores in roots, so you can afford to chop as new growth is pushed out, and I might even suggest now is a good time to do it because a) they can take the hit b) you are going to get Spring growth.
Happy for anyone to challenge this.