It takes me about 10 minutes to get ready to go. I will typically air up via the on-board compressor while I am eating breakfast or packing up. No one can hear that so its not part of my 10 minutes.
Then, I will disconnect everything - water, sewer, and electric.
Only then do I start the engine (and the generator if needed).
From there it will take about 5-10 minutes for the air to get to an acceptable level and for me to retract my jacks. I do a quick walk-around to make sure everything is good outside - takes just a minute. At that point, I hit the road.
I can't say, though, that I recall ever leaving before 7am from a campground and probably not before 8am. So, I'm not one starting my engine when its dark out.