You're right. I had not thought of the traffic on the holiday. I was probably thinking of the fact that my father, like our country, was born on that day.
I have been on the L.I. Expressway during afternoon rush hour and can attest to the fact that it will deserves its name of the "world's longest parking lot". That was 30 years ago, suspect that it is worse now.
When would you suggest holding it?
As to place, I like the idea of holding it at the Sherwood-Jayne house since it takes us back to our colonial/U.S. roots.