Our first class A was to tow our ski boat, didn't want to have to take 2 vehicles, and pay for, to go to the lake. The current A my wife has Lupus and needs to change positions often along with use facilities that would not be possible without stopping with any trailer.
Now when the kids were small we didn't let them move around while I was driving but at least when I pulled over there was always a clean bathroom and no matter the weather you could get to it, make a meal or go to bed. With small child that may be a big deal.
Is your current vehicle front wheel drive? If so you could rent a dolly or buy one used to pull what you have. We pull our 323i BMW behind our coach, coach averages around 7-7.5 mpg and the car averages around 26 mpg! so when we park the coach and explore we get really good gas mileage. Your current vehicle may get much worse mileage than normal if you are towing near or at it's tow rating.
Good luck with whatever you decide because in the end it is what works for YOU and your family not what works for any of the rest of us.