Using a flat/matte finish in a light color and getting an early start for the day will give you the best chance of getting 2 coats of paint done in one day. The higher the sheen on the paint, the more important it is to allow for that extra time between recoats. (As a general rule.)
I have had better success with a coat of primer and a coat of paint in a single day. I believe most fast-drying water-based primers have about 50% solids (give or take), perhaps this allows for the primer's faster dry time.
I tend to limit my use of fans to drying mud. I have had problems before with using fans on freshly-painted walls - from sagging and flashing to dust being thrown on the fresh paint... so use fans with caution.
If you are dealing with particularly humid conditions and thus much extended dry times, a dehumidifier in the room will offer better results than a fan, IMO. Just try to set it so it does not make the air TOO dry... the concept is to use the dehumidifier to bring the air's humidity levels back to normal, to allow for the normal dry times. Be careful not to dehumidify the air too much, or the paint will dry too fast and this can cause other problems.
But here in San Diego, the humidity and temp levels are perfect for natural quick dry times... in most cases, I can prime a room with Zinsser 1-2-3 or Gripper and it will be fully dry in well under 2 hours. Same goes for most flat/matte paints, even some eggshells and satins dry completely in 2-3 hours here. But for semi- and full glosses I will always wait the 4 hr minimum, and with some brands of paint I will not even recoat the glosses until the next day. (This is part of the reason most pros charge a premium for working with glosses - along with the extra skill they require.)
And finally, if you absolutely HAVE to get in and out of a room in one day, I would (again) suggest trying to get your hands on the new Benny Moore "Aura" paint. This paint was designed to cover in a single coat, given the color change is not drastic and the new color is not a deep tint... and it dries to the touch in ONE hour. Using deep tinted colors, you'll need no more than 2 coats, and I have recoated the matte and satin finishes in 2 hours with no problems at all.