Not F car related (sorry) but looking for tips on how to teach my wife to drive a manual

Your desire not to spend any money along with your desire to teach her to drive stick are in direct conflict. You need to either rent a manual trans car for her to practice on, risk burning up the clutch on one of your two manual cars, or just spend the money to have the car shipped. You're in a penny wise, pound foolish mindset here.

Best car I ever had to teach people stick on was a '77 trans am. It had nearly 400 lbs ft of torque, it was difficult to stall and a tap of the gas generally took care of that. The big problem with that one was not breaking anything or burning up the clutch, but giving too much gas and then you had a different skill you had to teach people. 2nd best was a 2004 Jeep wrangler sport with the heavy duty axle as it included 3.73 gears. That was difficult to stall and didn't have enough power to get people in trouble, but the clutch wasn't quite as robust as the trans am.

I would just do the drive, but take some back roads and plan a bunch of stops - heck just drive 4 hours and then spend the night, making that the vacation part of things. Then show up, drop the car off and hop on a plane back. If you don't enjoy road trips (especially in a manual trans Mustang GTR), you're either not a car guy or not doing them right.