Whatever said:I got about 1 lb from a Trainwreck in a 20 gal bag? It's been a few years on that one but the roots had plenty of room. I'm just saying transplanting can cost you a bit of time as the plant recovers. If done carefully no problem really but I try and avoid transplants and just give the plant a lot of soil to work with from the start. I think you might hit a half pound with that start and strain.
I think I'll play it by ear. I've always had great success with transplants because I transplant the whole thing and don't prune the roots. I just cut the bag and transfer everything that was in the bag to the bigger one.