I think the Green's will be saved by the fact that only 5 of their senate seats are due to go up for election at the next election, because of the half quotas.

The senators up themselves are:

• Hanson-Young in SA (The Greens will get at least 1 quota statewide in SA)
• McKim in Tasmania (Safe)
• Lee Rhiannon (Controversial, and was elected 9th in NSW in 2016, when only half a quota was required, I can see her losing her seat along with Leyonhjlem and the One Nation senator, who are also up)
• Janet Rice in Victoria (The Green's have a large enough base in Victoria that they should get a quota, although without Di Natale on the ticket it could go ugly, but Natale only got 40k first preferences last time, so the Green's should still scrape thorough.)
• Siewert in WA (Now this one is interesting, because there is talk that if the #3 green takes his seat, which I think he said he will - that some people wanted him to take the half term over Siewert, who would have been elected 3rd without Ludlum. The Green's did get more than a quota even without Ludlum's 1st prefs, so who knows, I'd still tip the Green's here with only one seat to defend, they have enough of a base and a history in WA to scrape through)