Adding Weight for driving in the Snow? 2 Questions

There’s no good reason to add weight to a FWD car.
There’s already considerably more than 50% (~60% typ.)of the total weight over the driving wheels.

Adding weight over the non driven wheels will make it easier to get stuck.

To get a 10% increase in the Ranger would take ~350lbs over the back wheels or somewhat less if it’s gathered by the tailgate and behind the rear axle.

p.s. I agree that putting the weight behind the rear axle will hurt handling by increasing the rotating moment of inertia.