You should be fine with a 2016 (with a new 12V battery). A weak 12V battery will not maintain sufficient voltage during the startup process to keep all of the control and communication modules functioning properly even though it may not test really bad. The 2015's did have some intelligent brake controller issues and I eventually had mine replaced (under the aftermarket extended warranty that I purchased when I bought the car) after getting tired of periodically resetting the DTC's and disconnecting/reconnecting the 12V battery to restore normal operation. It eventually got to the point of happening at least once a month before I had the intelligent brake controller (includes the master cylinder) replaced. I saw the dealer invoice that was close to $3,000 so the aftermarket warranty paid for itself.
Note for reference: The hydraulic brakes still work without electric assist, but the pedal will get close to the floor (may feel like it is on the floor because the pedal becomes really hard to press) and require much higher effort without assist. Also, there was a recall on the 2015 intelligent brake controller that was related to cold weather (just a software/firmware update).
Silver LEAF 2011 SL rear ended (totaled) by in-attentive driver 1/4/2015 at 50,422 miles
Silver LEAF 2015 SL purchased 2/7/2015; traded 8/10/2019 at 82,436 miles
White LEAF 2019 SL Plus purchased 8/10/2019