My 2720SL has a standard group of options (roof air conditioner, spare tire, awning, TV antenna). Ready for the road, with propane, but without water in the fresh water tank, water heater, toilet, or grey water tank, it weighs 3350 pounds. Yours will weigh as much or more. If your Windstar's tow capacity is 3500 pounds, please don't do it - even if the wife and kids DO follow in a car! And by the way, the 3500 pound rating applies ONLY if you bought the optional factory towing package. Since you are asking about mods, I assume you don't have it, so your rating is only 2000 pounds. Although you can make some of the mods yourself (tranny cooler), you probably won't change to a high-ratio rear end, for example. In addition, the Windstar won't accept a Class III hitch, which is needed for anything over 3500 pounds.
Ford has a pretty good web page for each of its models regarding towing. It is worth checking out. You didn't specify the year of your Windstar, but the web address will be something like
https://web.msslib.dealerconnection....000c588035d7a7
Sorry, but I don't think your Windstar would be a good tow vehicle.
Bill