Well, each tomato plant should have it's own very large pot if you are doing container gardening. They need a LOT of root room! Probably a wine barrel per plant would be great!
I had some CP's last year left over from a school garden that I didn't have room for. Popped them in the ground , thinking the gophers would get them, and they ended up sprawling all over the garden, giving me tons of large tomatoes!
Check out the container gardening forum if you're going to continue with the plants in pots! You'll be amazed at what they do in pots! HTH Nancy

Yeah, my Cherokees get VERY big (probably 8-10 feet). You definitely need a very large pot for them. A wine barrel would be the smallest I would go. See if you can get empty pots that some nurseries use for trees. Those are a little larger than wine barrels (more depth too). Those are what I use for container tomatoes.

thank you