@Agoo No one can provide meaningful advice insofar as what size a pot should be unless they rely on assumptions, primary among them is the assumption that you don't know better than to use a medium which disallows you to pot up to a significantly larger pot because it's excessively water-retentive. If the assumption is invalid, the premise is invalid. As I noted there can be situations in which, if the grow medium is appropriate, that you could move your plant to a 10 or twenty gallon pot filled with that grow medium. In order to suggest you should only pot up an inch or two in pot diameter and depth, the assertion is being that person has a handle on the current size of the root mass, the grow medium you will be using, and your watering habits; this, because all 3 are used to determine the most appropriate pot size, and that information hasn't been available. In fact, in most cases when growers repot instead of potting up, especially if it's the plant's first repot, more often than not the pot should be smaller than it's currently in; but again, that too pivots on your choice of grow media. and watering habits.
BTW - don't think you have run out and buy a pot with multiple drain holes. One DH is all you need. If you have 2 pots, one with a single half inch DH and the other with 10 or even 20 half inch DHs, if all else is equal, both pots will hold the same amount of water when they stop draining. The one with 20 DHs will stop draining a minute or two sooner, but the amount of water remaining in the soil will be the same. Reason: Water retention is determined primarily by the size of the particles that make up the grow medium and whether any internal pores in the particles are open or closed. The water that's best avoided is the any water held in the inter-particulate spaces - the pore space between soil particles (perched water). That is what primarily limits oxygen supply to roots of containerized plants and as a result it limits root function. Soil compaction is also an issue with plants because the compaction of the particles squeezes air out of the small pores between soil particles, which is primarily a problem associated with fine-textured media.
Al
