The bitwarden clients themselves do keep a cached version of the database every time there is a successful sync to the server, so if you were to take the server offline you could still view / export the data thankfully! You cannot make changes to the database according to that page and my own experience, though others have reported that they are able to. Additionally, it looks like this cache does expire (30 days on desktop, 90 on mobile).
Just make sure to not log out completely (this is not the same as locking the vault, which is fine), this wipes the cache immediately.
A couple of video game specific communities I'm subscribed to that I don't see here already:
[email protected]
[email protected]
And then this one is a genre based one:
[email protected]