Hambre_Hombre, G'day Mate.
"... from roughly Brisbane to roughly Melbourne" It will be rough nearly all the way.
Perhaps think about walking the Bicentennial National Trail or link parts of the trail to doing more frequent off trail walking. At times you could cut corners and head straight over mountains ranges.The BNT has it's wilder moments for sure. The BNT runs the length of the Great Divide from Cooktown in FNQ to Healesville in Victoria. The backbone of the BNT is the old travelling stock route network along the Great Divide. All different track surfaces are encountered from trackless wilderness, unformed roads on the Travelling Stock Routes, back country trails and fire trails and quiet rural roads and even skinny sheep tracks across private properties.
At times the AAWT and the BNT become the same trail, south of the ACT. Vehicles are not allowed on the BNT, unless a fire trail or rural road is part of the trail.
The BNT Association has guide books, that detail the route. The BNT has a network of section coordinators that can give you the latest track condition updates and say what works and what doesn't. You can even arrange to post your supplies ahead because some coordinators, like myself are happy to meet you on the trail with your supplies. Many coordinators have properties right on the trail, a big plus. I live only 5 minute's walk from the trail. If you join the BNT Association, you will get good backup ...
http://www.nationaltrail.com.au/ Andy Friend is currently riding his MTB on the BNT. Kerri, Andy's wife, is backing-up in their vehicle, lucky man. Andy's route description (for every day so far including rest days) is on his blog and the pick of his images are on his Facebook.
Andy started in Cooktown and is heading to Canberra. Andy is currently in the Kroombits. When Andy reaches Killarney (in about 3 weeks) close to the Border the trail gets more severe and less rural. The stuff walkers like?
http://www.andyfriend.com.au ...
http://www.facebook.com/TheFRIENDlyRideI'm a mountain bike coordinator, so I take a particular interest in the bike riders but I've walked a fair bit of the rough trail in NSW. Very few walk the BNT. Most travellers have pack-animals on the BNT. In Northern NSW you are about a month walking between towns. There is a MTB coordinator in Qld as well, Dave McLeod. All of the section coordinators and their contacts are listed on the BNT Site, in the Guide Books and in BNT Tracks Magazine, which is published 4 times a year for BNT Members.
Michael Rogers and his Mate Tom rode from Healesville to Canberra last February. Tom rode with Mike for part of the way. Michael's account is a classic with excellent videos and good track data ...
http://www.crazyguyonabike.com/doc/?doc_id=8146 One of the issues of multiple portages of a laden bike ...
http://www.youtube.com/watch?v=YMxb7NVim1A The high-vis shirt must have been needed to scare Dulugars.
These two reports will certainly give you an idea of the different character at times of the BNT.
When I've been planning my trips to work out access points, I think that there is only one set of maps to have to see the big picture for NSW. The NSW State Forests Maps. Killarney to Barrington Tops below, with my main track advisor Alice ... I need a bigger sitting room to get to the Victorian Border.
This is the topo detail from one of the NSW BNT guide books. The purple bits are extant Travelling Stock Reserves and a Travelling Stock Route.
As you can see from the map on the BNT site, the BNT goes almost exclusively along the Great Divide for 5,330 kilometres. An old Guide Book for the section 'Yaouk to Omeo' and one of the new Guide Books for NSW, from 'Jenolan Caves to Yaouk'.
Warren.