There were only 9 deep water ports in the CSA. Around 75% of blockade runners successfully avoided the blockade. There simply was not enough credit to finance more blockade runners nor were there ships available to haul more loads. This problem was self inflicted.
When the CSA government showed how very small their grip was on reality by embargo grill cotton exports, they effectively blockaded themselves. Had, as anybody with the sense god gave a duck, they exported every pound of cotton they could let hands on, a huge cash reserve could have been created. Goods & ships could have been purchased & delivered before the US Navy could have interfered.
Yes, without doubt more tons of supplies could have been imported… but it would have taken a wholesale replacement of the CSA government to do it.