I’ve previously used Bikesure who seemed ok.
If you have contents insurance, have a look into the PDS. Some insurers will cover it, but not while riding, while a number of others will cover it including while riding, as long as you’re not participating in races.
Covering it under contents insurance is likely much cheaper than specialist bike insurers.
Don’t worry, the experts are clearly focussed on fixing the lack of public transport as outlined by the very next paragraph after your quote above…
“A spokesperson for the Department of Transport and Main Roads said $1.529 billion dollars had been specifically allocated for road projects in the Moreton Bay region.”
Imagine how many trains and buses they could put on for that much money.