16qt should be good and how bout putting in 2 hides? I needed to do this with my little hypo girl and it has helped her tremendously. She went from not eating to being a great eater!
Also, I had a couple of snakes who were not nasty, but who really needed to just be left alone for a little over a month. No touching or holding or anything except tub maintenance.
Lastly, and I'm certain you already know this, get int ouch with Tim. All great breeders (Tim included) are happy to help with any problems