You certainly would see longer ranges for the same battery if you just swapped the cabling and motor over to superconducting versions, but there are kind of two scenarios at play here.
You have highway driving where a lot of your losses are mechanical due to high sustained speeds (air resistance and friction). Those wouldn’t go away, but your “electrical to mechanical” losses would be reduced, so you’d see modest improvements.
Then you have around town driving where your losses from accelerating and decelerating are much larger than the mechanical losses (air resistance and friction). Here with proper design changes I think you would see spectacular improvements in efficiency.
Unfortunately, this doesn’t help much with the EV ‘range anxiety’ issue haha. Go figure.