Oh my goodness, that is a tiny, tiny space! I have that exact hutch for my son's rabbit, I can't imagine having 4 hens in there for 5 days without getting out. Is there any other way, at all, to confine them while your gone? Do you have a garage or other building in which you could set up a temporary pen for them? There are also exercise pens that are made to attach to the front of those rabbit hutches, that's what we have for the buns. It's still not optimal for chickens but it would be much better then the hutch alone.