They will 100% spend big money this offseason. To me, the only free agents that seem to be a stretch are Rendon, Cole, & probably Strasburg (and I still believe they pursue both pitchers). Ultimately I see them settling for Bumgarner (who I like but is seriously overrated around here) or Wheeler (who I think is criminally underrated here) as their primary starting pitching upgrade. I fully expect a second rotation addition simply due to our lack of depth and Wood would be a fantastic option, although I could see them going cheaper there. Assuming we keep Colome & Bummer, I think only one bigger bullpen addition will be needed (Betances is a guy I’d love to add) as I’d expect Lopez to likely move to the pen at some point.
I fully expect Abreu back on a two year deal (in the $25M to $30M range). I still think they pursue Grandal to fill the left-handed void in the middle of the lineup and as a plus he won’t cost us a draft pick. Him, McCann, & Collins could basically rotate between C & DH for half a year until Vaughn is ready. They will also most definitely acquire a RF upgrade one way or the other, with a stopgap like Puig (until Walker or one of the AA guys is ready) a potentially cheaper option. I do like your Nimmo trade idea as well depending on the price.
So in summary let’s say you add Bumgarner ($20M), Wood ($10M), Betances ($12M), Grandal ($20M), & Puig ($12M). That’s ~$75M in payroll added to a base roster that’s probably sitting around ~$55M after extending Abreu and bringing back Rodon. All in you’re looking at a payroll of ~$130M, which would basically be league average.
Lineup: Madrigal (2B), Robert (CF), Moncada (3B), Jimenez (LF), Abreu (1B), Grandal (C/DH), Puig (RF), Anderson (SS), McCann/Collins (DH/C)
Bench: Garcia (UT), Cordell (OF), Mendick (IF), Collins/McCann (BC)
Rotation: Giolito, Bumgarner, Cease, Wood, Lopez (*Kopech to start in AAA)
Bullpen: Colome, Bummer, Betances, Fry, Herrera, Marshall/Hamilton, Covey/Banuelos (*eventually Lopez)
That seems completely doable to me and would be a team that should challenge for the AL Central title and/or second Wild Card spot in 2020.