According to this, we've got about $49 million in luxury tax cap space next year:
https://www.spotrac.com/mlb/washington-nationals/payroll/2020/So if we sign Rendon for say $32 million, that leaves $17 million to fill in the holes in the bullpen and the IF. Remember that Zimmerman, Cabrera, Adams, and Kendrick are all gone.
Figure Kieboom comes up as our every-day 2B. We add Zimmerman back for $2 million. Sign a LH 1B to platoon with him, and either bring back Cabrera or use Difo as the backup.
Potential relief pitchers under contact next year include Barrett, Doolittle, Elias, Glover, Guerra, Rainey, Ross, Suero, Strickland, Venters, Voth, and Austen Williams. Figure Strickland, Venters, and Glover are gone.
I don't see how we have enough room next year to extend Soto when he's only making about $580k next year.