Would it be worth it to pay $50 a month more for an extra 150 sq ft in an apartment?

I'm in the process of a divorce and am looking at apartments. There is a complex I'm interested in and the smallest apts are 550 sq ft and for $50 a month more, I can get the 700 sq ft. I also have a Great Dane. Is that extra space going to really effect her much either way? I work during the day, but I will be taking a walk every evening to allow her to get some exercise and she has plenty of toys and things to keep her occupied while I'm gone.