Sure a toy hauler would work great for all the kids bikes, toys and games. Mine works well to carry 2 pontoon boats for small lake fishing. If I don't have the quad in the back then I carry my camp stove and other stuff that usually ends up in the back of the pickup.
How do you figure a smaller living space? I have more avaliable room in my toy hauler then a conventional trailer because 8 feet of the back of the trailer is clean open space when the beds are up, plus if I wanted I could level up my ramp and add a ramp room to create even more space. The very back of the trailer is great for grandkids to play with there toys when the weather outside isn't so nice.