Tesla's are heavy for their size. More weight is more to move up a hill, it is also higher lbs.per square inch of tread as well.
My Model Y weighs as much as my old Jeep Quadra-trac truck did
They do have advanced traction control though, ground clearance is less than most Subaru's
The Grind Hard plumbing guy I ran into told me that I would be really surprised with how much traction the model Y has. They have built some wild off road vehicles.
We will see, I have new 18" wheels with Nokian Studded snows that are taller and narrower than the rubber band uber wheels and super low profile stock tires. My guess is the stock tires and ground clearance are the limiting factors on the 3 and Y