Well I had mine in our pole shed, and we have a warming room in there that I kept them the first few weeks in a LARGE rubbermaid tote that worked out just fine (started with 10, now have 8)
That was getting way to small way to quickly so just in the last week or two I moved them into a large wire style dog crate into the main part of the pole shed, I did have it in the warming room but I didnt have sides on it and they wound up pooping on the carpet through the wire...now they are just about 5weeks old and well that is even getting cramped for them I feel! So my plan is to finally build the nice 10x10 "stall" for them here within the week...
But the dog crate worked great, it has a pull out tray but I bed so deep it didnt work well for cleaning, kind of a PITA for cleaning but size and convenience it works great.