Suppressing current crawls while keeping older content public

So this is a unique question, and I don't know if this is the right forum for the question, but why not: 

We capture political campaign websites each election cycle, and part of our policy for is keeping content "embargoed" for six months before publishing. For new candidates, this isn't a problem. My question comes in for incumbents who are running for reelection. I want to capture new content (e.g. August 2020) by not make it available for six months (so February 2021).

However, the only way I can think to do this (since test crawls expire after 60 days), is to make the entire seed private, which would make all of the previously crawled content from the 2018 cycle hidden. I'd like to NOT hide the previous material (goes against my archival intuition). Is there any way to do this? The only other workaround I can think of would be to create the site as a new seed (which would be confusing, since candidates reuse their sites). 

Any ideas would be greatly appreciated!