Just forget about it, do a Prime timeline, post-TNG film, and don't mention it.
In my opinion, a simple 5 minute flashback would suffice. Just explain the backstory a bit. Enterprise, Deep Space Nine, Dominion War, blablabla. And only if it's relevant to the story of the film. If not, then you don't need to know it.
Lord of the Rings gave such a backstory exposition at the very beginning, and nobody complained about being "confused" by so much backstory.
It doesn't matter that there are 700 episodes, it doesn't matter AT ALL. All you need to know is the essence and gist of all of it, which isn't that much. There is the Federation, there is a famous line of starships, there was a big war, and that war is over now and that's it.
Heck, nobody complained about being confused by Old Spock's appearance in Abramstrek. His character has the "baggage" of 70 episodes and 6 films, and what did you need to know about all of it to get the film? NOTHING.
All you needed to know about First Contact was that Picard was previously assimilated. You didn't need to know how, you didn't need to know anything about later episodes with Hugh or Lore, nothing.
All those claims that the franchise somehow got caught up in its own continuity, and that audiences would be confused by so much baggage, is absolute rubbish.