OK, but if I go downstream from Cadwalader Ellis (what a great name), I hit Robert Ellis, Jr. , father in law of your aforementioned Sally Dehaven Sarah Ellis -- and we're in Sumner County, Tennessee, which is getting into Howton stomping grounds.
Backtracking Dehaven's, I find Anneken Margaretha de Haven , who I presume is Dutch. To be honest, Dutch and Welsh makes more sense to me than the Hugenot idea.
You have a lovely tree, rich in detail, and with much food for thought. I hope you don't mind if I bookmark it to study more.
Lieutenant John Ellis of Barnstable is my 6th Great Grandfather.
Here is another link to an Ellis database on Rootsweb.com
http://wc.rootsweb.ancestry.com/cgi-bin/igm.cgi?op=GET&db=garyg...