Not sure Chelsea are really an unknown quantity. They largely have the same side that won the league a few seasons back and it looks like Hazard and Costa are back to their best. Kante was also a very good signing for them and Conte is a great coach IMO.
Chelsea's main area of weakness is CB, everywhere else they have lots of quality.
I'd be surprised if we finished above them. I think the best we can hope for this season is 4th.