Can you? Yes with great care. You need to make it as stress-free for the plant as possible. Soak the soil ball well before moving then be sure to have the new container all ready to go first. Lightly fill the new soil in around the root ball and water it well adding more soil as needed.

If the plant is totally root bound (the whole root ball lifts out of the old container soil and all) then carefully make 3-4 spaced vertical slices in the root ball with a sharp knife about 1" deep and the length of the root ball.

Then move the container to a shady area for a couple of days and do not feed the plant until it begins to show signs of new growth on its own. Keep the soil in the new container only lightly moist so new roots can develop, do not over-water it

It is of course best to avoid the situation in the first place but given the choice between all the problems or even killing the plant by leaving it in too small a container or transplanting it to a larger one the choice is obvious - move it. Be aware that the odds are that not all will survive the process and those with fruit on them may drop the fruit before recovering.

For future reference, with the exception of some of the dwarf varieties 7-10 gallons is the minimal recommendation. Larger is better and especially so for the indeterminate cherry varieties. People mistakenly assume that because the fruit are small the plant and root ball will be too when in fact cherry varieties have some of the largest root balls of all.

Dave

Thanks Dave. I appreciate the instructions. I keep learning by doing. I watch as many YouTube videos that I can find each time I want to try something new.. The message I get is "ok, this is so totally going to work!" and it does for awhile until all of the things they don't tell you kick in, like the bucket is about to burst, or the top is so heavy it's going to topple over. Ah well. It's all lots of fun and I'l learning a lot. I figured the transplants would need a little TLC, so your welcome advice is most appreciated. These ten gallon pots just have to help get some plants through their crisis. In the future, the ten gallon sacks will be potato growing sack

IMO, if you are talking about the tomato plants that you have posted in another thread, I would say "NO". I would just let them run their course. Plants need moisture and nutrients to grow. In the case of tomatoes, their roots do not need more than a 5 gal. bucket. As I was pulling my tomato plants up, this past fall, I was paying very close attention to their roots size(planted in beds).
Obviously, if you provide them a bigger space, they will keep growing more roots an thus more foliage and not so much fruits that you want. Bigger pots have the advantage that need not as frequent watering as the smaller ones.