I would expose twice onto the same piece of film, using two different exposures. Use one for the ambient light, with the lamps off. Then turn the lamps on and do an exposure for them. A spot meter would help you immensely.
The other trick would be to ND gel all the practicals, and/or replace their lamps with dimmer ones. It is more work, but it will do the trick.
The less dark it is when you shoot the house/yard, the easier things will be.