Yes I did it April this year Prado 120 and GIC Extreme Offroad. From Tom Groggin once you Cross the Murray River ( about headlight height at the time and had a bit of movement. We entered and went to the right and then curved to the left towards the exit on the other side ) we went along Tom Groggin Track but we also drove Davies Plain Track and although tight at times I don't think you will have any issues. After that Mount Hope road. Beware of logging trucks as it got really dusty. From the. End of it you join the blacktop through Benambra, Omeo, and then Great Alpine way through to Hotham Heights were we went left onto Dargo High Plains road. We did it from Dargo to Tom Groggin and it was a long day including lunch, but we didn't travel down Davies Plain Track. I would allow 2 days minimum to allow a look around depending on your requirements . Dont drive through Omeo on Sunday. Nearly everything is closed . Hope this helps a little.
Cheers Frank