It's a small little igloo, but they are small little cats, so they manage to both squeeze in. I am sure they are better off and warmer curled up like that then in their own separate igloos -- although I have left the other empty igloo right nearby in case one of them changes their minds.
A very touching to me aspect of the story is that a few days ago I noticed that both cats had taken to sitting on top of my terrace table whenever I pulled my shutters closed and they couldn't sit on my window ledge. I put some warm fleece coverlets on the table, hoping that if they sat on those, I could then move the coverlets inside the igloos and the cats would follow, recognzing their own smell.
But all day yesterday I saw the cats sitting on the table next to the coverlets, not on them. So at the end of the day, after my own dinner, I decided to bring the coverlets back inside, since they didn't seem to be any attraction for the cats and I figured they would only get damp with the night air. But when I went outside, the coverlets were gone! I looked all around the garden, thinking they'd blown away or the landlord's big dogs took them, and it took me a minute or two to discover that my landord had apparently come by (or the dogs had dragged the coverlets to him) and he had arranged the fleece inside and outside the little domed cat houses to prevent any drafts from getting in.

Maybe he has the magic touch (or it could have been his wife) but for the first time both cats are snuggled up tight in the igloos. I am still going to buy them VetBed, because the fleece is not optimal I know, but for right now I am less worried about Paczski in particular catching a cold.