Another series, picking up right after the Dominion War, largely with new characters. I'd bounce between DS9 and the recovering Cardassia, with Garak as a major character. Other than Garak, I have no firm opinion on who I'd bring back, if anyone.
Jeffrey Combs would be welcome. There's no way the Weyoun template was stored only in the AQ so he could be resurrected. The fact that he's aged since then might be a problem, tho...we Vortas do tend to die young.
I'd want to keep Odo with the Dominion and I don't want him wussing the Founders out. There's no way one drop in the ocean can alter the whole ocean. The Founders can be peaceful...for now.

They know how to bide their time.
Turn it over to professional TV writers. If there are some novelists who can transition to TV writing, then hire them. The Reeves-Stevensons did well with ENT, after all.
The trouble is the cast... has umm... gotten older. It's still possible but... some of them have ahhh... aged.
Yeah, that kinda excludes the ones who can't be disguised by heavy makeup. Now that I think about it some more, I'm less inclined to make this DS9-centric. Center it on Cardassia with occasional guest visits to DS9, which by now would have all new personnel anyway.
The whole seven year arc would encompass Garak's drive to resurrect the Obsidian Order and wreak vengeance on the Dominion, which the Feds try and fail to stop. This causes the Dominion to counterattack and this time, they win.
Then for the next series, we get the "Starfleet guerilla warfare" idea that I wanted immediately post DS9 (after the Dominion won the war).