Any small container is fine. If it stays wet for too long, it's too big.
2-3" wide or smaller is a good starting size.
As far as how large the final pot size should be depends on how large of a plant you want to grow. Generally, 'they' say 1 gallon per month. Also, if soilless, you can use less.
Whateer you choose.. after harvest, pull it out and look at roots... is it too sparse with a lot of wasted/unused volume of medium? Is it too dense and wrapped around 100 times at bottom? Adjust based on what you see. How quickly you have to re-irrigate is a good way to choose pot size too... Exactly what you want can depend on soilless vs soil methods etc, too.
As long as it doesn't cause stagnated water for sitting overly wet for long periods of time or drying up before you can re-irrigate, it's the right size. When i pot-up to final 5-gallong size, it might take 4-5 days for 'next' irrigation, initially, but ramps up to every day or every other day once full size -- i'm in soilless, so more frequent is a good thing for me. If it's drinking quickly enough, it has to be making use of the volume.