Glenn got me buggered how yours weighed in at 1660 with an extra axle under it even empty maybe I had better use another weighbridge.
Stan Good roads all the way especially if you go up the centre and then theres no hills so you aren't holding anybody up if dawdling, well good roads by Aussie standards but I like going up through QLD as it's a bit more interesting but the roads are a bit worse especially when you meet a roadtrain on a narrow single lane and need to head for the scrub but no problem if you pay attention and check everything each day.
We usually take about 2-3 weeks to get somewhere like Wyndham but could take more if we find something interesting having the boat on means you need to be careful of roads and have marine destination target but plenty of spots to launch on the way from your place.

Murray great but only summer, Spencer Gulf and even St Vincent gulf again summer, then nothing until Boroloola (macarther system and sir edward pellew islands) great for several months in the dry season but goat track and rough roads with some dirt, trailer does it easily, the Roper River rough road and some dirt but launch at the Bar and leave trailer at store (great fishing and beautiful river but nearly 200k's to mouth).
If still heading to the Kimberlies The Victoria River is worth a launch and a couple of weeks but I haven't had the

in it yet just dinghies at various times, from there Lake Argyle is definitely worth a look and sail but got bored after a week as not much fishing

but magnificent scenery actually the good kimberly scenery starts not far out of Katherine, the words that come to mind are beautiful and especially big.
You can launch at Lake Kununurra but didn't impress but be better get supplies (good) here before heading out to Wyndham there is a supermarket at Wyndham but limited supplies.
You can stay at the Caravan park (Wyndham) in the unpowered area and leave your trailer there safely but we left the truck and trailer at the boat ramp in Wyndham on advice from local copper, there are five major rivers which run into the Cambridge Gulf and all are worth exploring especially if you have a dinghy for fishing, unlimited sailing opportunities especially if you want a buzz heading through the tight bits near the mouths of the Ord river with an outgoing tide and a cross or following wind but definitely a daytime project (trust me) great sailing and exploring from there to the mouth and some magificent scenery and waterfalls with great fishing (Barra) on the west side.
Out the mouth there is some great scenery and fishing around Cape Dommet (and West) but you do need maps and tide times, we carried two anchors and set long scopes everywhere as the tides are vicious and patchy winds so better to find sheltered anchorages although just out from the boat ramp is good most times when near Wyndham but the anchorage at Lacrosse Island is rough (trust me) but can be managed by using a bridle and two anchors.
It's pretty rare to anchor in 8m of water and be beached at low tide as you have to allow for tide moving you over shallower water but great experience and one of the places I really would love to do again in the

From Kununurra or Wyndham there are some great local road trips eg Bungles and el questro or home valley but you can get to home valley if you like an adventure with the tides and rocks

(never hit any) up the pentacost river.
Suggest for road trips have camping gear and be set up for several days or a week also some great gorges etc up the Gibb River road (can be rough).
You could travel from Wyndham around the coast to Derby or even Broome but definitely get proper maps and good local knowledge, I wouldn't do it with the wife but would with someone prepared to cop it rough if caught out as with the islands, tides and winds there can be wild and confused water especially if pushed for time and would also need? a satellite phone or HF radio for weather reports.
Time for bed but Darwin is a great place too and heaps of other rivers around there esp towards Kakadu.