No, you won't be towing a fifth wheel with an SUV and you do need a truck and yes a 3/4 ton truck. You should have bought a regular hitch camper to accommodate the parent, maybe you should concentrate on trading the trailer and not the SUV.

Why did you buy a 5th wheel trailer without the ability to move it?

No, Your Excursion cannot tow a fifth wheel trailer, you need a pickup, at least 3/4 ton with the proper equipment in the bed.

Your Excursion can tow a standard type of travel trailer with the proper hitch on the rear.

The information you have is correct.
You can not install a unit to pull a 5th wheel on your excursion.

custom build a fifth wheel dolly. kinda like the ones used on big trucks towing double trailers.
just be extra carefull when it is in use as there may be some stability issues.
Best bet is a differint trailer or second truck.

No there is no possible or i guess legal way to pull a 5th wheel with a suv. you should sell your 5th wheel and then buy a weekend warrior type trailer with a regular ball hitch. i hope this helps. if you go to extreme measures you could cut the back top of your suv off therefore making it a pick up like an avalanche. then you could close off the opening and attach a hitch in the back of the suv but that would end up costing as much as just buying a regular type trailer.