~ two hours, but usually much more (and yes, I have a permanent set up). My approach is methodical. I typically spend a couple of hours alone in TheSky determining how I want to frame the object it question. Should I do a mosaic etc. Then plan the acquisition times to shoot the blue, Ha or Luminance frames when the object is high. Blue in particular to minimise atmospheric extinction. Finally create the acquisition script which I then upload into ACP. I have a list of targets, times, camera rotation values etc. for varies targets based on the season.
I guess if we don't include the planning, then the time would be considerably shorter. Simply upload the script, cool the camera, sync the pointing model via a plate solve and I'm away. Probably 10 mins at most.