:) Hi, your Expedition is close to what my Navigator is. My Navigator has a payload of 1,600 lbs. and a tow rating of 8,900 lbs. My trailer has a GVWR of 6,300 lbs and an actual tongue weight of 900 lbs. This leaves about 700 lbs for me and my wife and some other stuff in my Lincoln. Also a 35' trailer is 10 feet longer than mine and will become a big sail when the wind hits it. My opinion is to have a trailer close to 25' and no more than 7,000 lbs. for your tow vehicle.
Another way to figure it out is to figure the tongue weight of a maxed out trailer and start deducting everything from your payload rating.
