No, I haven’t lost my mind, yet, but I had to share an idea that Norm came up with, which I thought was brilliant!  I have been wanting to move the kitty boxes out in the garage, with a pet door installed in the interior door going out to the garage.  The only problem is, that one of our cats is totally indoors, so we run the risk of her getting out when we opened the overhead garage door.  Norm suggested that we build an enclosure in our garage–maybe 3′ deep x 4′ wide x 2′ high.  That is just a guess since we have two cats with their own litter boxes.  Anyway, the enclosure would probably be plywood, with insulation board, to keep it energy-efficient, and have a hinged top allowing for easy access to clean the boxes out.  We would cut an access door for the cats in the wall instead of a door.  Here is a layout of how it would look:

We could trim the door out to match the rest of the house. 

What do you think?