I know RACQ will recover you pretty much anywhere they can get to themselves subject to your size. Even that depends on who is on the ground, because the size limit is to allow regional contractors an out if they don't own larger tilt trays etc. RACQ regularly recovers vehicles and trailers with roadside issues right throughout Cape York, including the OTT. There is no 2wd- only restriction. RACQ Ultimate basically ensures I will be recovered anywhere in Australia. They advise members to contact them not the local club and they secure recovery for the member. If for instance, NRMA basic level (the reciprocal arrangements are all basic level) can't handle my recovery, a private contractor will be used (and that might even be NRMA). Really remote areas are an issue more than difficulty of tracks/terrain. RACQ will reimburse some maybe all of your costs if you need assistance in parts of the Simpson or Gibb River Road. I have heard about a Vic driver on the 4x4 meet needing to get his vehicle towed to a "main" road before RACV would assist but that was insurance not breakdown (4x4Earth has that tale).

https://www.whichcar.com.au/gear/advice-roadside-assistance-in-the-bush

All of the roadside assistance companies use the same contractor to provide cover for a particular area. Therefore it won't matter if you are with RACV or RACQ or Youi or Club 4x4, if the recovery vehicle can get to where you are they will get you. The difference will only be in any cost to you subject to the Terms and Conditions of your particular cover.

Friends of ours broke down on the Tanami were "recovered" by the RACQ highest care. The recovery was 400kms, the contractor said it would have cost $2400.

We had used them when our Jayco Eagle did a wheel bearing + on the Hume Hwy. They took the van from Tarcutta to Gundaghai, while we drove. I was on the 2nd to top RACQ listing.

If you were going to travel on the Gun Barrel Highway, I'd ask questions first!