I was going to replace the wine with chicken broth? Any creative and tasty suggestions besides alcohol? Verjus, more beef broth, vinegar, etc?

Would love to know how it comes out. Am thinking of making it too.

That's a great idea that completely escaped me! My local gourmet market sells homemade beef demi glace and I believe that very brand. Making this is a couple of hours, so off I go to purchase. Thank you.

I know Williams-Sonoma, Dean & Deluca, etc. carries demi-glacé too, but I'm not sure they sell smaller quantities like the company above.

I may need more coffee but I can only think of one thing you haven't already mentioned, to use some demi glace in place of the 1/2 cup of white wine. For this sauce, you could buy a very small amount, dilute with a little water and sub for the white wine. I happen to like this vendor because they sell in very small quantitites.
http://www.morethangourmet.com/pantry-stock-sauces-gourmet-soups/meat-based-sauces-a-stocks/french-demi-glace