If you think the defense we have seen the past six games is indicative of what to expect the rest of the season, no trade will adequately address the litany of problems it has shown.
If you think the defense will play similarly to how it performed last season, which certainly wasn't good either, but better than the past six games, the Wings would need to trade for a #2/#3 defenseman. I don't think a trade for a top four D will cut it. I think Buff would sorta fit that criteria, but I haven't seen a single Jets game this season and my opinion isn't very informed at this moment.
Other than Buff, I can't think of any targets that would qualify as a top three defenseman the Wings could realistically trade for.
Holland can't trade/sign for another stop-gap defenseman like Zidlicky or Ian White and expect it to make any difference.
He either needs to be ultra aggressive or take his tire and go home.
The situation the Wings are in sorta reminds me of the 1997 Spurs. David Robinson missed almost the entire season and that resulted in the Spurs winning the lottery that season which ended up getting them Tim Duncan. That one awful season resulted in the Spurs winning a title two years later and set them up for four more championships and potentially several more over the next decade.
If the Wings did have a terrible season, drafting in the lottery one season might be enough to set them up for the short and long term if they get lucky and draft an NHL ready defenseman who immediately improves the blue line. It's a long shot, and once Datsyuk returns, he will make the Wings too good to potentially draft in the lottery.