I have seen it done with clones before like six of them I think. I would definetly transplant them into the 22 gal. rubbermaid early into flowering, this way they won't straggle each other to death with their roots.

Honestly, I don't have any experience, just from what I've seen with the clones and common sense. They have to get pretty rootbound to die and it also varies from strain to strain, some can take it, other can't. I doubt they would max out a 22 gal. if you put them in right before flower say...a week to let them adjust.