It depends .....
From another post: "How large a container needs to be, or CAN be, and how much soil a planting needs/will tolerate before drainage & saturation is an issue depends on the 3-way relationship between plant mass, container size, and soil type. We often concern ourselves with "over-potting" (using a container that is too large), but "over-potting" is a term that arises from a lack of basic knowledge about the 3-way relationship noted, which should logically determine appropriate container size(s).
It's often parroted that you should only move up one size in containers when "potting-up". The reasoning is the soil will remain wet too long and cause root rot issues, but it is the size/mass of the material and soil type/composition that determines both the upper & lower limits of appropriate container size - not consecutive volume progression.

Plants grown in slow soils need to be grown in containers with smaller soil volumes so that the plant can use water quickly, allowing air to return to the soil. This (smaller soil volumes) and the root constriction that accompanies it will cause plants to extend and gain o/a mass much more slowly - a bane if rapid growth is the goal - a boon if growth restriction and a compact plant are what you have you sights set on.

Conversely, rampant growth can be had by growing in very large containers and in very fast soils where frequent watering and fertilizing is required - so it's not that plants rebel at being potted into very large containers or volumes of soil per se, but rather, they rebel at being potted into very large containers with a large volume of soil that is too slow and water-retentive.

We know that there is an inverse relationship between soil particle size and the height of the PWT in containers. As particle size increases, the height of the PWT decreases, until at about a particle size of just under 1/8 inch, soils will no longer hold perched water. If there is no perched water, the soil is ALWAYS well aerated, even when the soil is at container capacity (saturated).

So, if you aim for a soil composed primarily of particles >1/16", there is no upper limit to container size. The lower size limit will be determined by the soil volume's ability to furnish water enough to sustain the plant between irrigations."

You can grow a very small plant in a very large container if the soil holds little or no perched water (saturated soil).

Al

Let me be more specific. Suppose I use your recommended gritty mix (1/3 bark, 1/3 turface, 1/3 granite).
Would a 10 gallon pot be appropriate?

PJ

The 1:1:1 mix holds no, or almost no perched water, so you can grow the tiniest of plants in very large containers full of that soil. You're gonna hate me though, when I answer "yes and no" to your question. Yes if the entire soil mass is comprised of the gritty mix. No, if you just plop the soil mass into a dissimilar soil in a large container. Large volumes of dissimilar soils in the same container will always present irrigation related problems.

Al