Transplanting Advice Needed

I’ll save the back story of my callous, black hearted, soon to be ex-wife and get to my question.

I’m forced to transplant my fist year Chinook and Cascade from my garden to containers. They were planted April 3rd and are roughly 6 feet tall. My question is this: how big is the root structure? I’d like to keep as much of it intact as possible when digging it up to prevent unnecessary growth stunt.

BTW, if anyone out there is looking for large cheap containers skip the nursery. Buy one of those large plastic circular containers with rope handles made for keeping beer and soda on ice from that big awful store that sales everything under the sun at ridiculously cheap prices.

Another suggestion for containers...wooden barrels cut in half. Tyranenna Brewery in Lake Mills, WI sells their used barrels for $10. They're no good for brewing, but perfect for yard decor.

As for transplanting... the roots shouldn't be too much to deal with at this point, but I'd be worried about moving a 1st year. When I take my rhizomes up every 2-3 years to prune the root ball, they're usually about 2'x2' clusters give or take a little. That's with 2-3 years of growth though.