Well there is no definite answer, but I'd say; if you're careful, it will be better to get them in the ground.
By leaving them in the bucket they may get root-bound this year, so the transplant may help your yield. The transplant is, even in the best case, a little bit of a stresser.
Do what ever you choose while the plant is still dormant, this will keep stress way down.
One option is to leave them it the pot, and just cut out the bottom, or bottom 1/3. This will keep the rhizomes in a confined space, but allow the tap root grown to grow down to India.
Or just kick over the pot and pull out the plant.
After transplant (maybe just before too) some B vitamins in the water will help reduce shock. You can use "Superthrive" or just dissolve a "B complex" supplement (the ones for human consumption). I don't really know the proper dosage, but it has been shown to help transplants of annuals. If the plant is fully dormant this is probably not worth wile, as the plant isn't soaking up any water, and therefore won't get any of the B. And it's hard to shock someone who's in a coma.
If you pull the plant out, notice how big they are in comparison to what you planted last year... as long as you don't try to kill them and can provide enough food and light for them; you'll get a good yield this year.