Back when it was just me and I didn't have many clothes, I did exactly what you do! Especially when washing at laundromats, like heck was I going to pay to do two separate half-loads!
But what we do now is this. We have a 3-bag sorter like this
that fits nicely just behind the door of our bedroom. One bag holds darks, one holds lights, and the third holds linens/towels. We drop clothes into the right bag as we undress, and when a bag is nearly full it goes to the washing machine. It makes it so easy to stay on top of the laundry!
I use a separate basket tucked inside my closet for delicates, and a separate basket in DS' room--almost all of his clothes qualify as "darks" so I just dump his basket into the dark bag in our room every few days.