your looking 3.5-4 hrs straight down the hwy over gateway bridge turn off at the warwick bypass before ipswich over the range into warwick as long as the traffic is light and no accidents
I come from North Brisbane and the best I can say is to avoid cities in peak hour... spent more time in city than on highway.
I'm headed out to Talgai and Thanes Creek this week, if you see a bright blue Focus say hi!