[rwmj]

Now I'm wondering if anyone has built a very large grid of resistors to try to approximate / curve fit this. Surely there's a youtube video in this ...

[Kirr]

Well there is this: https://www.youtube.com/watch?v=v1YrANSmOGY - Not sure if it counts as large, but it's a start.

[BizarroLand]

I imagine that a 100x100 grid of resistors all terminated in a massive resistor would be the same as long as you kept to the middle of the grid for testing.