I did almost the same recipe back in April. I didn't have any brewing yeast on hand so I tried some of my roommates baking yeast.
First thing you need to know, its that it will be good. It will have a light taste, with an EXTREMLY DRY finish.
I used 2 cups of Dextros for 3.5 L (call it a Gal) and it fermented and cleared in about 14 days. I only let it age 5 days at it was Victoria Day (Canadian National Holiday) and everyone at my BBQ wanted to try it.
From what I have read, traditional style bakers yeast ferments out at around 10%. This must have been closer to 15% though, because one glass and I things got nice and comfy.
Ah! Now I'm excited for my cider to come up!
Anyhow, unless you are looking for a specific FG, I would leave it in the Demi-John untill it clears - then wait 3 or 4 more days. Rack for a week or two and have at it.
I'm new to all this two, so let me know how it turns out.