Ford Expedition 2012 EL Limited 31 foot Trailer

This one might be more of question of short wheelbase vs trailer length, rather than tongue weight vs GVWR. Depends on your threshold of comfort along with distance and type of terrain.

My opinion is 2k lb less trailer and 26-28' max based on towing a 6300 dry 26' with a standard 1/2 ton truck with 145" wb. It was great when conditions were favorable but when the wind picked up, not fun.