Victorian High Country with Camper Trailer

I think the OP was after suggestions of tracks from the forum.
Taking into account they are towing a camper trailer and that two weeks after they travel most of the tracks in that area close for obvious reasons as well as recent rains through out Victoria it would be my recommendation that they head along this route:-
Mansfield - Bonnie Doon - Yarck (drop in for a coldie) - Yea - (nice pie shop) - Yarra Glen - Lilydale - Cockatoo - Pakenham - then onto the Princes Highway at Nar Nar Goon turn off at Stratford before heading up Beverley's Road and following the signs to Dargo.
Apart from some minor roadworks this should be tar all the way and not create any risk.
Seriously though - at this time of the year I wouldn't be towing my mother in law through that country in a billy cart.

That's a good idea, but it's Mt Hotham you want!

Gday Nifty
I new that , im having bad day.

Hotham is correct. The boom gate at the Hotham end of the Dargo Road will be down and locked well before June as will almost all of the gates in the high country. The ski season officially starts Queens Birthday weekend in June although there is often no skiable snow then. However most gates to 4wd tracks are locked in May in anticipation of imminent snowfalls.