We've got two nice insulated cat houses for our ever-changing ferals population (as fixed as possible!) with insulation, off the ground, straw & electric outdoor approved cat heating pads. New dilemma: both houses are currently occupied one, with a sweet little blackboy who's become quite a fixture "Crosby" but a new little 7 month old grey (VeRY feral although we're working!) has shown up so we spayed her, but she LOVES Crosby, our black one who sleeps in our insulated dogloo. So much so she sleeps curled up in the dirt right in front of the dogloo. so sad! We want to do a shelter for her right next to Crosbys, but don't have much room. I'd like to fit in a heated outdoor cat pad ( min size seems to about 17" x 14") - obviously I'd want a way in, and room for straw and maybe additional insulation ....the "two rubber maids inside each other" sold at most clinics are too big---any thoughts, or places I can be pointed so I can make my on? I'd like to keep these two sweeties together, & it's getting cold quickly! That dirt rug won't work much longer!!! Thanks!!!!