I think I would suggest an ex-pen where he has the ability to get out play with his toys , put a nice soft bed, lots of toys and a pee pad and food and water.. his little bladder is soo tiny he most likely will not be able to hold it that long. You can purchase an expen or a child play yard and keep all this things in there, if your worried about your floors I would buy a shower curtain liner at the dollar store, put the crate, bed , food toys and pee pad in the ex pen.. this way he is not confinded for several hours over night and then all day long while your gone.. that seems a little excessive for a tiny pup and he most likely will have accidents in his crate!
Kennel-Aire Exercise Pens - Exercise Pens - Crates & Kennels - PetSmart
I have the childs play yard which is plastic, check craigslist before you purchase a new one!