If this arc had been done on Deep Space 9 instead of TNG, Picard would have been a Borg for the entire season. At the very least, rescue him in Part II but take several months to deBorgify him.TBOBW: Part 1 was stellar and a perfect set-up, but Part 2 kind of blew it. Picard was rescued way too early. After that there wasn't much reason to care anymore.
I think one of the main differences between TNG and DS9 was the latter being highly serialized, like most current dramas (BSG, Lost, etc). TNG had a habit of hitting the reset button every week, and there was little by way of continuity.
how exactly would it have worked for Picard to remain a Borg for the entire season? It was one cube on a direct mission to conquer Earth and the Federation. Either they succeed and the show's over, they're destroyed and Picard is killed in battle, or they're defeated before they reach their goal,which given how fast they move, would have to come quickly after "BOBW I," and Picard is successfully rescued(the option we got, of course)
Given what was known of the Borg at the time, having one cube with Locutus on it as a recurring enemy would just not have worked.
And we did get a follow up on his "de-Borging," in "Family."