Friends of Baw Baw are doing a working bee up there soon on May 15th (?) attending to the drainage on the walking tracks. In winter the Mt.Erica hike is more demanding. It is becomes very cold , snowy , icy and visibility is often quite poor. The track up to the campsite is harder to make out in the snow. Quality snow shoes such as MSR lightning ascent snow shoes make a big difference. The track is not really ideal for skinning up on BC XC skis. XC Skiing down it would be tricky unless you are really good at skiing . :-0.
NBW hut is easy to find once you have located it in green season. It is a public hut. The Scout Hut is also easier to locate once you have been there in green season. The Scout hut is locked to the public. Mushroom rocks gets snow in winter. Jann's hut a.k.a Stagg's hut is also easy to find once someone has shown its location to you. That gets snow too.
Mt. St. Gwinear is an easier way to get up onto the plateau in winter on BC XC skis or snow shoes and do some snow camping . Take a snow shovel if you go in late August so you can dig your tent in ,out of the wind if necessary.
I have snow shoed and XC skied up there. I enjoy BC XC skiing up there in late winter/ early spring.
The car park for MSG is not that far away from the summit of MSG so if the weather at the rock shelter turns feral you can bail out quite quickly. Be careful of creek crossings in September. The snow bridges are melting then and taking a tumble into the icy water is not fun!.
If you start really early you can go from MSG car park to Baw Baw village and back in a day on skis or snow shoes following the pole line. If you camp at East Tyers campsite a.k.a O Shea's Mill the night before then you can get a proper early start on that trip .You must carry snow chains and a snow shovel.
Navigation ability in a white out is a necessary skill.