We stayed there last November -- DH and me, my mother-in-law and our 8 and 10-year-olds all in one room. It went swimmingly, and we had plenty of space for everybody and their stuff (granted, we pack light: a 21" suitcase and a tote/backpack per person, and everybody was extra-tidy).
One thing we found was that there are only 4 or 5 drawers in the room, half of which are not accessible when the Murphy bed is down. (One of the "sets of drawers" in the photo above is actually fake - it's the door to the refrigerator cabinet, decorated to look like drawers.) In contrast, there is lots of space for hanging clothes in the dressing/sink area (not to mention tons of under-sink storage for toiletries and such). What we did was: (1) DH and I brought our own slim hangers from home so we could hang most of our clothes and MIL could use the half-dozen hangers that Disney provided; and (2) we brought a set of collapsible hanging shelves to put on the hanger bar, so I had a place to put things that otherwise would have needed drawer space, like packing cubes of the kids' clothes, swimwear, etc. (I'll post a photo below - the shelves folded flat and took up almost no space in my carryon). Also, to save space in our luggage and in the room, we brought just over half of the clothes we needed, and I did laundry mid-week. (The laundry facilities are by the quiet pools, and you can monitor the progress of your washer or dryer via the LaundryView website, so you'll know, right down to the minute, when it's done.) There's a shelf over the top of the hanging bar, but it's so high up that it was no good for MIL and I to conveniently reach or use -- but it was the perfect spot to put all of our empty suitcases!
Another tip: Disney supplies enough coffee pods for 2 regular cups (and 1-2 decaf, I think) each day. If all three adults are coffee drinkers and want to use the in-room coffeemaker for their morning cup of coffee, leave a note for your housekeeper to leave extra! And with that many people using the bathroom, a travel-size spritz bottle of "Febreeze To Go" spray (it's marketed as a fabric refresher, but it works just as well to "clear the air" in tiny bathrooms) is also nice to keep around!
Have fun, and enjoy CBR!