Typing this from Wyndham. We made it to Broome via the highway, with grand intentions of coming back via the GRR. After a guided trip via bus to Windjanna and Tunnel Creek (excellent btw), and noting the heat, the quality of the road, and how dry some gorges (eg Windjanna) were, we revised that to coming back via the highway and just ducking into the Bungle Bungles and then ElQuestro and Home Valley.
Made it to Bungle Bungle van park, and decided "far out, it is hot". Only about 37 or 38, but little/no shade. Other park visitors coming back and saying they cut their walks short due to the heat. With a two hour drive each way plus walk needed to see anything, we decided to leave that for next trip. At 6am, I could feel my skin burning. Got here, and decided we could not survive ElQuestro without air con, and for the prices asked we would be better off coming back when it was more enjoyable. The pool in Wyndham CP is nice, as are the trees.
So planning on going to Kunnurra (didn't see everything on our way across) and then Zebra Mine. Turns out Zebra mine is closed for the season already. It is not alone, as various places are starting to close up. First of September all the Victorians start heading home for the bowls season, the tourist numbers drop and cafes etc reduce their hours, regular markets are no longer held, and heaps of other services reduce or stop operating.
We knew there would be issues coming this late in the season. A couple of weeks ago we had a great time at Kununurra, but you could see the tourist numbers were already dropping as waterside camp spots were easy to get. Will be interesting to see what it is like tomorrow. The climate and facilities on the road across have changed more than I expected in such a short time. Heck, we are even noticing changes in what the plants are doing (flowering/fruiting etc).
IMHO doing it in October would feel like an endurance event. You would also miss out on the opportunity to do lots of cool things, as they would simply be closed. You could brag that you did it, but would be reluctant to go through it again.
Save it for later, and do something fun instead.