There was no window.
Tuvix could have made a deal.
"One more month, and then I'll gladly let you murder me."
Remember in the Jaime lee Curtis/Lindsay Lohan Freaky Friday when they tried to switch back into their original bodies by running at each other REALLY fast like angry foot ball players into a violent collision?
That may not have rebuilt Tuvix with the regular Tuvok and Neelix, but what about the Quicksilver Neelix and Tuvok?
The problem with my description of a benevolent (Peace Corps) Borg is that that was the TNG Borg. The Borg on Voyager were just a bunch of thug assholes mostly, which is why they kept picking on Voyager. However since they always knew where Voyager was, when ever Janeway said that she had reversed course and hid from the Borg (Which she said they did a lot in Dark Frontier) is hilarious because Voyager was never actually really hiding effectively or at all fro the Borg all the times she thought they were hiding.... Ever played hide and seek with a 3 year old?
Long range transwarp scans from one Cube can map everything in the galaxy and keep track of everything in the galaxy since then can bisect the bastard in a matter of weeks... Just Like Voyager at puny warp speed can scan and chart what's happening a couple weeks in either direction of where it's standing with it's regular subspace scanners because if it couldn't that rickety barge should have been a lot more indecisive.
You know when you want to change the TV channel, but you'd have to stand up, and walk three feet to get the remote, so you say fuck it and just watch whatever the hells on, THAT is why the Borg did not assimilate Voyager.