Don't use Versabond if you expect to keep your time schedule. You are pushing your luck.
Use the RS (rapid set) thinset from Home Depot and you can grout in about four hours after setting the tile.
Rapid set won't get you in any trouble if you don't mix too much ahead of your ability to install the tile and once it begins to stiffen up in the bucket, get rid of it and mix a new batch.
I'll bet you are working with a room that isn't any larger than 35 square feet and you and a helper can easily turn that room around 100% in twelve hours.