Can structure with plumbing sit on floating slab?
I used to live in a mobile home in Montana. The lot was compacted gravel and the home sat on a number of cinder block stacks leveled with wood wedges between the block and frame. Water and gas were connected to the home using a 2 foot length of flexible pipe. We never had a problem with frost heaving. Just be certain to insulate and run a heat tape around the water pipe and skirt the home properly. Skirting will pay for itself by your second month of heating your home.