You can grow a full grown plant; Or actually "finish" a plant in a small pot. As long as you provide nutrients to the plant, and despite it being root bound.

However; You will get a fuller plant and a higher yield if you transplant from 1 gallon pots into 3 gallon pots at flower stage.

Since plants stretch 2-3 X's when photo period is changed; It is advisable to put them in bigger "3 X's bigger" pots at flower. Hope this helps.