I'd water limited amounts and not be looking to see water draining out of the bottom of the container as that would mean you're saturating the entire 5 gallons. It might only take a few cups of water each watering to keep the plant healthy in the first week or so and as the grow progresses just gradually increase watering for the size of the plant. I don't think anyone though can tell you exactly how much you'll need. Would be the person growing understanding and recognizing when the plant is thirsty.

Course if you transplant correctly (HD has a sticky on his procedure) you could transplant a number of times and not shock the plant. I've never had a plant show any signs of shock from transplanting. From me being a stupid grower yes. But not from transplanting.