The cold front tomorrow should affect most of the state including the NW. Probably only 1-5mm up there but there could be isolated higher falls.
10-15mm general on and south of the ranges.
The low to follow is being treated very differently by different models. GFS has it winding up right in the sweet spot for most of VIC with huge accumulated multi day totals of 50-100mm widespread on and south of the ranges, 10-25mm north of the ranges and 100mm plus in coastal areas, particularly coastal ranges.
EC paints a very different picture and after a quick check around the southern half of the state on yr.no, doesn't seem to have that much rain at all.
IMO it should line up more with the GFS scenario, and depending how close the low gets to central VIC, there could be widespread heavy falls.