I owned 2 Explorers, 96' & 01'. They were both great vehicles but even towing a small 16' center console boat was a lot for the short wheel base. I don't know about the newer models but trans were not the best in the older ones.
I also went from a 07' Tahoe to a 08' GMC 2500 CC 6.0 SB towing a 30' Xlite Cougar. The Tahoe did ok but the GMC was so much less stressful. You can see my current TV in my sig. I love it but also wish I had gotten the same vehicle in a 1 ton SRW.
Unfortunately all budgets are not created equal. I found that it would have actually been cheaper for me to have upgraded my TV earlier, to the right one (for us). Some half ton CC's may meet your needs but a CC 3/4 or full size van may be better choices. They give more flexibility.
A friend had a camper & TV combo that was barely adequate. He had to tow with minimal stuff & tanks all empty. He upgraded his TV after he had to turn down a boon docking trip with several friends because he couldn't add the water weight.
I don't think a dully is needed for everything but suggest you purchase the largest (tow capability) TV that meets your family needs, & that you can afford. Good luck in your search.