Mike, yep, if your comfort zone is between 20 -28 and no problems ( mine more about 22-30 ) with that not far north of Brisbane in August.
As I have already said, I live along the Queensland Coast where it is shorts and Tshirt during the day all year around, even sunbaking weather whilst walking on beach with top off in last few weeks and that is likely to continue as we have already had our little bit of winter coolness - maybe another few days to come if forecast is correct but by end of July we are usually into the warming up even further.
You can take it from a local that our weather up here is just great this time of the year and just keeps getting better.
It's a great time to be relaxing out in the sun and that is one reason why many holidaying visitors do come from southern parts including Victoria in winter, to experience some winter warmness, certainly not cooler weather.
I also lived on the Gold Coast for a number of years and yes, there are differences to what you can get there as to several hundred kilometres north of Brisbane, winter storms there not unknown of as are overnight frosts that we had a few of in various years so going north of Brisbane, you will find a little more of the summery warmth, even the Sunshine Coast being a much more relaxed environment seeing as it has not had anywhere near the same extent of highrise developments as the Gold Coast has had, I think of it as akin to a concrete jungle and traffic is something any holiday maker can do without.