I think I'd sit the deadline out*. First and foremost, if last season taught us anything it's that there's no sure thing. I don't have any regrets, they shoved everything in for what ended up being Bergeron's last year. But despite having the most talent I've ever seen it didn't get them any closer. They could add Connor McDavid, Cale Makar and Matthew Tkachuk and that doesn't gurantee anything.
Secondly, they've burned a ton of futures already. At some point that bill comes due. They made 5 draft picks in 2023, have only 3 left for 2024, and are down 2 in 2025. I'm in the minority that thinks they are good at drafting but given the high bust rate for all draft picks, they need volume.
As for depth, I think they're in OK shape. Defensively they currently have Lohrei, Zboril and Mitchell in Providence. I don't think trading a late pick is going to bring someone back that is any better than those guys. At forward, they've got Beecher, Poitras, Steen, Brown and then the prospect types like Lysell and Merkulov they could use. Obviously injuries could change the calculus but again, not sure I'd trade a pick or prospect to bring in a depth player. I'd prefer to just ride it out with what they've got.
* Everyone is focusing on Elias Lindholm but the only real exception, in terms of a *big* trade targets the Bruins could chase after, is Noah Hanifin. There's a more immediate need, he's local and they've been linked to him in the past, and the timing lines up well. Grzelyck and Forbort are pending UFA's so he's an immediate upgrade and there's an opening on the left after this season. Hanifin just turned 27 so he's close to the same age as when they acquired and extended Hampus Lindholm. Fits in age wise with the McAvoy, Pastrnak core. I would rather wait and sign him as a UFA and save the assets but he's the only real *big* name trade target I could see them spending for.