“Is that GG Polycro material tougher than standard 1.5 mil plastic drop cloths? If so I think that's what I'll get.”

Some more thoughts.
Yes it is tough. After a few years, I have no pin holes. It is getting stained. It picks up ground moisture soooo easy; so I pack it away in the morning wet and dry it out in the afternoon.

You can get the same stuff at Lowe’s, Home Depot, or Menard’s. It’s called Indoor Window Shrink Film. You heat it to seal to your window. That’s why you don’t want to store the ‘ground cloth’ on the outside of your pack or it shrinks.

If you want stronger yet polycro, get the Outdoor Window version. The weight will go from 1.5oz to 2.5oz for your footprint. Now we’re talking overkill.

This is how I got a big enough polycro for my TT Rainshadow.

-Barry