Well not sure it's any solace but they will make a trade. They have to because they have too many people to protect from the rule 5 draft in december. I suppose they could wait until the offseason but given how they've talked it makes as much sense to trade now as then. It's just that who they trade for isn't going to be a giant impact outside of something like the Ross trade that's been mentioned.
I mean think about the situation they are in. Unless you are trading away one of Soler, Russell, Castro, Bryant, or Rizzo you can't improve 1B, 2B, SS, 3B, and RF and even with Castro you could feasibly still play Baez at 2B. As for C/CF/LF, of players with 100 PAs for the cubs, Coghlan is 3rd on the team in OBP. Montero is 4th. Fowler is 6th and for what it's worth Deno is 5th. So, if they continue using Cogs/Deno in LF that's one of their best "players."
So, in terms of hitting the upgrade has to come from within with Soler/Castro/Russell playing better. As for pitching, their starting pitching has been great. They were third in fWAR last I checked. And while I could perhaps see them making an early play to add someone now rather than waiting and spending loads of money it's not a "must have" type situation.
Ultimately, I'm guessing they will probably nab a bench bat for the OF and send Baxter down. I could also see them adding a younger BP arm. They could really use a good young lefty. Russell has been decent this year but he is what he is which is a LOOGY and not really a impact BP piece. Wood has been decent as a reliever as well but with Jackson gone he's your long reliever too. Rondon, Grimm, Strop and Ramirez would appear to be "the future" of the pen going forward and are all righties. Motte, Medina, Soriano and Schlitter are both expendable and also righties. And Rosscup while having good numbers in the minors is possibly a bit raw still and he's really the only lefty of note high in the minors.