Forget about that 6200 lb tow capacity. That number is considering a 150 lb driver, with no passengers or cargo. If you only weigh 150 lbs and plan on towing alone, with no cargo, you might tow that kind of weight.
Besides that (mythical) tow capacity number, you also need to watch the hitch rating, GVWR, and payload. All of the ratings fit together like a puzzle.
GVWR -- Gross Vehicle Weight Rating. ---Max amount the vehicle can weigh. Includes everything and everybody in, or on the vehicle.
GCVWR --- Gross Combined Vehicle Weight Rating -- Max combined weight of tow vehicle and trailer. Includes everything and everybody in, or on both vehicles.
Payload -- Difference between what the vehicle actually weighs and it's GVWR. This is the weight capacity you have for people, tow vehicle cargo, WD hitch, and trailer tongue weight.
Hitch rating -- Maximum amount of weight on the hitch receiver (with and without weight distribution).
As you load weight into the tow vehicle (people, cargo, hitch, etc), the max tow capacity and available payload, go down pound for pound.
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Example:
If the vehicle has 6200 lb tow capacity and 1100 lbs of payload, and you load 600 lbs of people, your tow capacity and available payload drop to 5600 lb towing capacity and 500 lbs payload.
A 5100 lb wet weight trailer, will need about 700 lbs (with WDH) of available payload.
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Depending on size and weight of your family, the Grand Cherokee may, or may not have the capacity (payload) to carry everything and everybody you plan to bring along.
