I'll preface this by saying I haven't figured out all the money, so maybe more astute Celticsbloggers can correct me there if need be. Also, this is about the team a few years down the road, so it may be premature but it's January so whatever.
Except for a major, star-getting deal, I want to keep the Brooklyn assets and the Memphis pick. As much as possible, keep the core together, draft intelligently, and tweak the roster with trades and free agency to improve the weak spots. If we do this, I think we can contend for the next two seasons and maybe this one as well.
The summer of 2019 is where it gets interesting. Jaylen will be entering his 4th season, the 2017 Pick his 3rd and the 2018 Pick his 2nd. The Celtics will likely have their own draft pick plus those of the Clippers and Grizzlies that summer which could be anywhere. Assuming they're still around, Bradley and Crowder will be 29, Thomas will be 30, and Horford 33. Crowder will be on an expiring deal and Horford will have a player option for his last year ($30 mil).
Assuming Horford picks up his option, the C's will be in a good position to either let things ride or, if they want, make some big trades with players who should still be attractive for teams wanting to compete.
This is all contingent on the C's drafting well, getting a little lucky, and not making any dumb free agency moves, but if things break right, we could have a fun team that wins 50+ games to root for a couple of years and then immediately have a really talented team mostly under the age of 24 that can compete for the next decade. I'm just marveling now at how well positioned this team is to never have to go into a full rebuild and be in contention for home court advantage every season for a long time, as long as they take care of business.