Cumbrian Lakes is in the south section of Poincianna Blvd. Poincianna has many subdivisions being built off of it. It would take you about 15-20 min to get to Disney. You head straight up Poincianna cross 192 and take Osceola Parkway right to Disney.
http://www.thedibb.co.uk/villa/map.htm
http://www.orlando-maps.info/top_down_maps/kissimmee_top_down.htm
You can get a more detailed map when you click on the flashing hands.
We haven't stayed in Cumbrian Lakes but have travelled the road. It's like being on a country road until you get up closer to 192 and then it gets really busy.
At the north end of Poincianna where it intersects with 535 there's a SuperWalmart and if you turn left at the intersect about a half mile on the right is Lake Buena Vista Outlet Stores. Of course there are lots of restaurants along 192 and a SuperTarget around mile marker 12. There's plenty of signs to show you the way to Disney.
