Familiarity with navigation by GPS in poor visibility in winter e.g. snow and the environment you are traversing would be a prerequisite over the season rating of your tent (what else do you have suitable for winter, specifically?). Coordinating GPS with a hard copy map and getting safely out of situations like sudden whiteouts or storms would be the first thing to touch base on.
It's a bit of a long hike from SA to Victoria's alpine country. I note you are interested in snow, but bushwalkers also do the Great Ocean Walk in winter, seeking the quieter times over the hectic and rather dirty summer-autumn period. The Grampians/Gariwerd can be very wintery but only the higher, exposed peaks get snow, and then not very frequently.
Nothing to be gained convenience- or economy-wise from going into the ski resorts (Hotham, Falls) without being proverbially screwed for a pretty penny.
But there are el cheapo (kind of...) alternatives; you will still be pinched a penny and a pound for entry fees.
Mount Stirling, opposite Buller, may be of interest; simply park the chariot at Telephone Box Junction and walk (or ski-walk-ski-walk) to Bluff Spur Hut, and camp in the immediate environment, as is so very popular (and fun!) in winter. You have the attractiveness of snowy alpine scenery all around and the robust refuge of the hut if you really get ... ahhh ... cold feet!
Stirling had a miserable winter period last year, closing early. It is sometimes necessary to walk 3 to 4 or more kms to get on skiable snow. From Bluff Hut, Stirling Summit and it's iconic snowgum (which has sprouted healthy, bushy babies!) is within reach, though best only in clear conditions. There are other back country skiing/overnighting destinations, but Bluff Hut would serve as an excellent introduction for orienting yourself and equipment (strengths and weaknesses, and stuff you forget to pack!) to the different alpine environment, snow or no snow, and the very changeable weather that is a characteristic.