Just checked my Avplan tracks, they show off blocks time and take off time.
On average, I take 7.5 mins from off blocks to take off.
From my tie downs to the run up area is 730m and it's another 50m to enter the runway.
Lilydale is grass, typical taxying speed is 6-8knts ground speed - 10kts is too fast for the uneveness of the surface.
Doing the math, it takes 3.6mins to taxi to the run up bay. Allow 3mins for run ups, and then 1 min to enter and take off.
Hope that helps in your planning.