The truck and flat-bed idea has been considered, but not implemented successfully.
The Kimberley Karavan will NOT sleep 5 people; and it requires a choreographer for even two people to move around easily inside.
Kimberley Karavans and Kruisers have electronic level indicators in their water tanks. However, they are quite unreliable. Many Kimberley owners have installed flow meters in their place for much greater accuracy.
The number of complaints in the Facebook group is several hundred, with many around the fact that the campers and caravans are Chinese made kits that are assembled in OZ.
Lemon Caravans in Australia
There is an Australian Facebook Group called "Lemon Caravans & RV's in Australia". It was set up to advise the public about shoddy workmanship and support in the Australian Caravan industry and to lobby for legislation to protect consumers. There are no Lemon Laws...
It's been down for months, and the domain registration has now expired. That probably says a lot. CAVEAT EMPTOR!!!!
As to your other question, Warren T near Montreal can probably help you out. He posts frequently on Pointedthree.com.
Mastodon
The registration for their website domain name has expired, which probably tells a lot.
EP really needs to remove their name as a sponsor of this forum.
Kimberley put a 12 volt membrane heater across the bottom of my main water tank. Never tested it for freezing protection, but it certainly should be helpful/