The projector will work even in this small space, but keep in mind that it will only shine on a small part of the walls. In this case, you could get more units and set them in a line to cover the full range of the house.
Another possible solution might be installing the laser unit in a tree or on top of your house and pointing it downward to the yard. If you decide to use such a solution always think safety first and use appropriate solutions to hold the unit in place.
For more info check out our Ultimate Guide to Laser Xmas Lights – http://laserchristmaslightshq.com/ultimate-guide-christmas-laser-lights/
Or our Holiday Projector Guide explaining the five highest quality and most affordable projectors on the market – http://laserchristmaslightshq.com/best-laser-light-projectors/