I don't know about public transport but it's a big uphill walk from Boonah to Frog, you'd want to hitch this part for sure and there may not be that many people heading up there so you could be in for a wait. Assuming you get there ok you'd be relying on others to give you lifts into town for supplies or facing a monster walk there and back. The thing is there might not be too many people there at times, though around school holidays there probably will be. I won't say it's not possible but it'll certainly be a pain in the arse.