I'm trying figs in containers for the first time, in hope to bring them inside my garage or shed in winter. I'm border 6b/7.

I have a brown brown turkey and 2 Chicago cold hardy. I am planning on keeping one on the deck and "submerging" two planters partially in ground. I found three 22" wide by 22" tall (they taper to 20" on bottom) planters made of good resin/plastic that are "shatter resistant" that I was hoping to use. The trees are currently 3-4', potted.

Ive searched and search about using containers but haven't found exact sizes to use. Obviously these are bigger than the nursery pots they have come in. Will those sizes be suitable, suitable just for awhile, and if not, how big should I go?

Thanks for any advice! It's greatly appreciated